Immune checkpoint inhibitor (ICI) which enhances the antitumor activity of T cells by blocking the programmed cell death protein 1 (PD-1) or cytotoxic T lymphocyte antigen 4 (CTLA-4) pathways, has shown breakthroughs in cancer therapy and has been effective in the treatment of EC in recent years (7, 8). The gene discussed is PDCD1; the disease is cancer.