PDCD1 and cancer: After this treatment, some long-term survivors began to be observed; however, the improvement in the 5-year survival rate was extremely limited.3, 5 Immunotherapy has significant effects in many malignant tumors, and especially, programmed cell death 1 (PD-1)–programmed cell death 1 ligand 1 (PD-L1) blockade can induce durable tumor suppressor effects.