PDCD1 and neoplasm: It was demonstrated that tumors with DNA repair deficiencies (n = 230), particularly in the dMMR pathway, which can accelerate mutation rates and impact prognosis, have significant potential to be used as biomarkers for TMB, neoantigen load, and tumor-infiltrating lymphocytes in patients undergoing anti-PD-1/PD-L1 therapy [98,101].