CTLA4 and hepatocellular carcinoma: Studies have shown that overexpression of immune checkpoint molecules such as PD‐1, CTLA‐4, lymphocyte‐activation gene 3, T‐cell immunoglobulin, and mucin‐domain containing‐3 in HCC contributes to T cell exhaustion and CD8+ T cells apoptosis, thereby promoting immune escape.245, 246, 247