This new anticancer approach, which aims to fully utilize the body’s own immune system to resist and fight cancer and kill cancer cells by blocking the PD-1/PD-L1 signaling pathway, has successively defeated nearly 20 major solid tumors, including colorectal cancer, substantially improved the survival of patients with advanced tumors, and has become a ‘special effect’ drug for patients with tumors [9,10]. The gene discussed is PDCD1; the disease is cancer.