The emergence of immune checkpoint inhibitors marks a new era in cancer therapy, and their continuous evolution has brought major breakthroughs in cancer treatment.[1] As the preferred treatment for advanced cancer, immune checkpoint inhibitors have achieved remarkable success in melanoma, non-small cell lung cancer, esophageal squamous cell carcinoma and other tumors.[2] Programmed cell death protein-1 (PD-1) is a cell surface receptor present on T cells. Here, PDCD1 is linked to cancer.