Immune‐checkpoint molecules PD‐1, LAG3, CTLA4, TIGIT, and HAVCR2 (TIM‐3) have been identified and studied in various cancers including liver hepatocellular carcinoma, lung adenocarcinoma, stomach adenocarcinoma, ovarian cancer, and peritoneal carcinoma.59, 60. This evidence concerns the gene PDCD1 and ovarian cancer.