| 1. | Siegel RL, Miller KD, Jemal A. Cancer statistics, 2020. CA Cancer J Clin, 2020, 70(1): 7-30. | 
				                                                        
				                                                            
				                                                                | 2. | Zhou M, Wang H, Zeng X, et al. Mortality, morbidity, and risk factors in China and its provinces, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet, 2019, 394(10204): 1145-1158. | 
				                                                        
				                                                            
				                                                                | 3. | Wang M, Wang Y, Feng X, et al. Contribution of hepatitis B virus and hepatitis C virus to liver cancer in China north areas: Experience of the Chinese National Cancer Center. Int J Infect Dis, 2017, 65: 15-21. | 
				                                                        
				                                                            
				                                                                | 4. | 中華人民共和國國家衛生健康委員會醫政醫管局. 原發性肝癌診療規范(2019 年版). 臨床肝膽病雜志, 2020, 36(2): 277-292. | 
				                                                        
				                                                            
				                                                                | 5. | Disis ML. Mechanism of action of immunotherapy. Semin Oncol, 2014, 41 Suppl 5: S3-S13. | 
				                                                        
				                                                            
				                                                                | 6. | Zhang H, Chen J. Current status and future directions of cancer immunotherapy. J Cancer, 2018, 9(10): 1773-1781. | 
				                                                        
				                                                            
				                                                                | 7. | Finn RS, Qin S, Ikeda M, et al. Atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma. N Engl J Med, 2020, 382(20): 1894-1905. | 
				                                                        
				                                                            
				                                                                | 8. | Zhang Q, Lou Y, Bai XL, et al. Immunometabolism: A novel perspective of liver cancer microenvironment and its influence on tumor progression. World J Gastroenterol, 2018, 24(31): 3500-3512. | 
				                                                        
				                                                            
				                                                                | 9. | Byun JS, Yi HS. Hepatic immune microenvironment in alcoholic and nonalcoholic liver disease. Biomed Res Int, 2017, 2017: 6862439. | 
				                                                        
				                                                            
				                                                                | 10. | Hato T, Goyal L, Greten TF, et al. Immune checkpoint blockade in hepatocellular carcinoma: current progress and future directions. Hepatology, 2014, 60(5): 1776-1782. | 
				                                                        
				                                                            
				                                                                | 11. | Han Y, Chen Z, Yang Y, et al. Human CD14+ CTLA-4+ regulatory dendritic cells suppress T-cell response by cytotoxic T-lymphocyte antigen-4-dependent IL-10 and indoleamine-2, 3-dioxygenase production in hepatocellular carcinoma. Hepatology, 2014, 59(2): 567-579. | 
				                                                        
				                                                            
				                                                                | 12. | Hammam O, Mahmoud O, Zahran M, et al. The role of Fas/Fas ligand system in the pathogenesis of liver cirrhosis and hepatocellular carcinoma. Hepat Mon, 2012, 12(11): e6132. | 
				                                                        
				                                                            
				                                                                | 13. | Pardoll DM. The blockade of immune checkpoints in cancer immunotherapy. Nat Rev Cancer, 2012, 12(4): 252-264. | 
				                                                        
				                                                            
				                                                                | 14. | Wei SC, Duffy CR, Allison JP. Fundamental mechanisms of immune checkpoint blockade therapy. Cancer Discov, 2018, 8(9): 1069-1086. | 
				                                                        
				                                                            
				                                                                | 15. | Gibney GT, Weiner LM, Atkins MB. Predictive biomarkers for checkpoint inhibitor-based immunotherapy. Lancet Oncol, 2016, 17(12): e542-e551. | 
				                                                        
				                                                            
				                                                                | 16. | Cheng AL, Hsu C, Chan SL, et al. Challenges of combination therapy with immune checkpoint inhibitors for hepatocellular carcinoma. J Hepatol, 2020, 72(2): 307-319. | 
				                                                        
				                                                            
				                                                                | 17. | Samstein RM, Lee CH, Shoushtari AN, et al. Tumor mutational load predicts survival after immunotherapy across multiple cancer types. Nat Genet, 2019, 51(2): 202-206. | 
				                                                        
				                                                            
				                                                                | 18. | Kudo M. Scientific rationale for combination immunotherapy of hepatocellular carcinoma with anti-PD-1/PD-L1 and anti-CTLA-4 antibodies. Liver Cancer, 2019, 8(6): 413-426. | 
				                                                        
				                                                            
				                                                                | 19. | Karwacz K, Bricogne C, MacDonald D, et al. PD-L1 co-stimulation contributes to ligand-induced T cell receptor down-modulation on CD8+ T cells. EMBO Mol Med, 2011, 3(10): 581-592. | 
				                                                        
				                                                            
				                                                                | 20. | Xu F, Jin T, Zhu Y, et al. Immune checkpoint therapy in liver cancer. J Exp Clin Cancer Res, 2018, 37(1): 110. | 
				                                                        
				                                                            
				                                                                | 21. | El-Khoueiry AB, Sangro B, Yau T, et al. Nivolumab in patients with advanced hepatocellular carcinoma (CheckMate 040): an open-label, non-comparative, phase 1/2 dose escalation and expansion trial. Lancet, 2017, 389(10088): 2492-2502. | 
				                                                        
				                                                            
				                                                                | 22. | Zhu AX, Finn RS, Edeline J, et al. Pembrolizumab in patients with advanced hepatocellular carcinoma previously treated with sorafenib (KEYNOTE-224): a non-randomised, open-label phase 2 trial. Lancet Oncol, 2018, 19(7): 940-952. | 
				                                                        
				                                                            
				                                                                | 23. | Finkelmeier F, Czauderna C, Perkhofer L, et al. Feasibility and safety of nivolumab in advanced hepatocellular carcinoma: real-life experience from three German centers. J Cancer Res Clin Oncol, 2019, 145(1): 253-259. | 
				                                                        
				                                                            
				                                                                | 24. | Yau T, Park JW, Finn RS, et al. CheckMate 459: A randomized, multi-center phase 3 study of nivolumab (NIVO) vs. sorafenib (SOR) as first-line (1L) treatment in patients (pts) with advanced hepatocellular carcinoma (aHCC). Ann Oncol, 2019, 30: v851-v934. | 
				                                                        
				                                                            
				                                                                | 25. | Finn RS, Ryoo BY, Merle P, et al. Pembrolizumab as second-line therapy in patients with advanced hepatocellular carcinoma in KEYNOTE-240: a randomized, double-blind, phase Ⅲ trial. J Clin Oncol, 2020, 38(3): 193-202. | 
				                                                        
				                                                            
				                                                                | 26. | Qin SK, Ren ZG, Meng ZQ, et al. A randomized multicentered phase Ⅱ study to evaluate SHR-1210 (PD antibody) in subjects with advanced hepatocellular carcinoma (HCC) who failed or intolerable to prior systemic treatment. Ann Oncol, 2018, 29(suppl. 8): LBA27. | 
				                                                        
				                                                            
				                                                                | 27. | Qin S, Ren Z, Meng Z, et al. Camrelizumab in patients with previously treated advanced hepatocellular carcinoma: a multicentre, open-label, parallel-group, randomised, phase 2 trial. Lancet Oncol, 2020, 21(4): 571-580. | 
				                                                        
				                                                            
				                                                                | 28. | Wainberg ZA, Segal NH, Jaeger D, et al. Safety and clinical activity of durvalumab monotherapy in patients with hepatocellular carcinoma (HCC). J Clin Oncol, 2017, 35(15_suppl): 4071. | 
				                                                        
				                                                            
				                                                                | 29. | Lo B, Fritz JM, Su HC, et al. CHAI and LATAIE: new genetic diseases of CTLA-4 checkpoint insufficiency. Blood, 2016, 128(8): 1037-1042. | 
				                                                        
				                                                            
				                                                                | 30. | Hodi FS, O’Day SJ, McDermott DF, et al. Improved survival with ipilimumab in patients with metastatic melanoma. N Engl J Med, 2010, 363(8): 711-723. | 
				                                                        
				                                                            
				                                                                | 31. | Sangro B, Gomez-Martin C, de la Mata M, et al. A clinical trial of CTLA-4 blockade with tremelimumab in patients with hepatocellular carcinoma and chronic hepatitis C. J Hepatol, 2013, 59(1): 81-88. | 
				                                                        
				                                                            
				                                                                | 32. | Butow PN, Turner J, Gilchrist J, et al. Randomized trial of conquerfear: a novel, theoretically based psychosocial intervention for fear of cancer recurrence. J Clin Oncol, 2017, 35(36): 4066-4077. | 
				                                                        
				                                                            
				                                                                | 33. | Yau T, Kang YK, Kim TY, et al. Nivolumab (NIVO) + ipilimumab (IPI) combination therapy in patients (pts) with advanced hepatocellular carcinoma (aHCC): Results from CheckMate-040. Chicago, IL, USA:  Presented at the American Society of Clinical Oncology Annual Meeting, 2019. | 
				                                                        
				                                                            
				                                                                | 34. | Lee M, Ryoo B Y, Hsu C H, et al. Randomised efficacy and safety results for atezolizumab (Atezo)+bevacizumab (Bev) in patients (PTS) with previously untreated, unresectable hepatocellular carcinoma (HCC). Ann Oncol, 2019, 30: v875. | 
				                                                        
				                                                            
				                                                                | 35. | Kudo M, Motomura K, Wada Y, et al. First-line avelumab + axitinib in patients with advanced hepatocellular carcinoma: Results from a phase 1b trial (VEGF Liver 100). J Clin Oncol, 2019, 37(15_suppl): 4072. | 
				                                                        
				                                                            
				                                                                | 36. | Qin SK, Chen ZD, Liu Y, et al. A phase Ⅱ study of anti–PD-1 antibody camrelizumab plus FOLFOX4 or GEMOX systemic chemotherapy as first-line therapy for advanced hepatocellular carcinoma or biliary tract cancer. J Clin Oncol, 2019, 37(15_suppl): 4074. | 
				                                                        
				                                                            
				                                                                | 37. | Sun T, Zhang W, Li Y, et al. Combination immunotherapy with cytotoxic T-lymphocyte-associated antigen-4 and programmed death protein-1 inhibitors prevents postoperative breast tumor recurrence and metastasis. Mol Cancer Ther, 2020, 19(3): 802-811. | 
				                                                        
				                                                            
				                                                                | 38. | Wei SC, Levine JH, Cogdill AP, et al. Distinct cellular mechanisms underlie anti-CTLA-4 and anti-PD-1 checkpoint blockade. Cell, 2017, 170(6): 1120-1133. | 
				                                                        
				                                                            
				                                                                | 39. | Wolchok JD, Chiarion-Sileni V, Gonzalez R, et al. Overall survival with combined nivolumab and ipilimumab in advanced melanoma. N Engl J Med, 2017, 377(14): 1345-1356. | 
				                                                        
				                                                            
				                                                                | 40. | Datta M, Coussens LM, Nishikawa H, et al. Reprogramming the tumor microenvironment to improve immunotherapy: emerging strategies and combination therapies. Am Soc Clin Oncol Educ Book, 2019, 39: 165-174. | 
				                                                        
				                                                            
				                                                                | 41. | Shigeta K, Datta M, Hato T, et al. Dual programmed death receptor-1 and vascular endothelial growth factor receptor-2 blockade promotes vascular normalization and enhances antitumor immune responses in hepatocellular carcinoma. Hepatology, 2020, 71(4): 1247-1261. | 
				                                                        
				                                                            
				                                                                | 42. | Zhang W, Bi XY, Sun YK, et al. Preliminary results of sintilimab plus different dose of IBI305 (anti-VEGF monoclonal antibody) in patients with advanced hepatocellular carcinoma: A phase Ⅰb study. J Clin Oncol, 2020, 38(15_suppl): 3079. | 
				                                                        
				                                                            
				                                                                | 43. | Ikeda M, Sung MW, Kudo M, et al. A phase Ⅰb trial of lenvatinib (LEN) plus pembrolizumab (PEMBRO) in unresectable hepatocellular carcinoma (uHCC): Updated results [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019, 2019; Atlanta, GA. Philadelphia (PA): AACR. Cancer Res,  2019, 79(13 Suppl): Abstract nr CT061. | 
				                                                        
				                                                            
				                                                                | 44. | Llovet JM, Kudo M, Cheng AL, et al. Lenvatinib (len) plus pembrolizumab (pembro) for the first-line treatment of patients (pts) with advanced hepatocellular carcinoma (HCC): Phase 3 LEAP-002 study. J Clin Oncol, 2019, 37(15_suppl): TPS4152. | 
				                                                        
				                                                            
				                                                                | 45. | Kudo M, Finn RS, Qin S, et al. Lenvatinib versus sorafenib in first-line treatment of patients with unresectable hepatocellular carcinoma: a randomised phase 3 non-inferiority trial. Lancet, 2018, 391(10126): 1163-1173. | 
				                                                        
				                                                            
				                                                                | 46. | Tesniere A, Schlemmer F, Boige V, et al. Immunogenic death of colon cancer cells treated with oxaliplatin. Oncogene, 2010, 29(4): 482-491. | 
				                                                        
				                                                            
				                                                                | 47. | Chiang CL, Chan ACY, Chiu KWH, et al. Combined stereotactic body radiotherapy and checkpoint inhibition in unresectable hepatocellular carcinoma: A potential synergistic treatment strategy. Front Oncol, 2019, 9: 1157. | 
				                                                        
				                                                            
				                                                                | 48. | Chew V, Lee YH, Pan L, et al. Immune activation underlies a sustained clinical response to Yttrium-90 radioembolisation in hepatocellular carcinoma. Gut, 2019, 68(2): 335-346. | 
				                                                        
				                                                            
				                                                                | 49. | Pinato DJ, Cole T, Bengsch B, et al. 750PA phase Ⅰb study of pembrolizumab following trans-arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC): PETAL. Ann Oncol, 2019, 30(Supplement_5). | 
				                                                        
				                                                            
				                                                                | 50. | Kaseb AO, Cao HST, Abugaba YI, et al. Final results of a randomized, open label, perioperative phase Ⅱ study evaluating nivolumab alone or nivolumab plus ipilimumab in patients with resectable HCC. J Clin Oncol, 2020, 38(15_suppl): 4599-4599. | 
				                                                        
				                                                            
				                                                                | 51. | Shi XJ, Jin X, Wang MQ, et al. Effect of resection following downstaging of unresectable hepatocelluar carcinoma by transcatheter arterial chemoembolization. Chin Med J (Engl), 2012, 125(2): 197-202. | 
				                                                        
				                                                            
				                                                                | 52. | Sun HC, Zhu XD, Huang C, et al. Initially unresectable hepatocellular carcinoma treated by combination therapy of tyrosine kinase inhibitor and anti-PD-1 antibody followed by resection. J Clin Oncol, 2020, 38(15_suppl): e16690. | 
				                                                        
				                                                            
				                                                                | 53. | de Miguel M, Calvo E. Clinical challenges of immune checkpoint inhibitors. Cancer Cell, 2020, 38(3): 326-333. |