Because anti-cytotoxic T lymphocyte–associated protein (CTLA)-4 antibodies and anti-programmed cell death protein (PD)-1 antibodies have shown therapeutic effects in various cancers, studies have shown that T cell immunoglobulin mucin-3 (TIM-3), a new immune checkpoint molecule, plays an important role in the development of HCC. This evidence concerns the gene CTLA4 and cancer.