Immune checkpoint inhibitor therapy for malignant tumors in liver transplantation recipients: A systematic review of the literature

•The evidence on safety and efficacy of immune checkpoint inhibitor (ICI) therapy for liver transplantation (LT) recipients is limited.•A systematic literature search was conducted, and 24 articles with 41 LT recipients who received ICI treatment were included.•Allograft rejection occurred in 31.7% of patients, death was reported in 46.3%, and 10 patients responded to immunotherapy.