PDCD1 and neoplasm: Specifically, immune checkpoint markers, including programmed death 1 (PD-1), programmed death ligand 1 (PD-L1), and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) were expressed at higher levels in the low-risk score group, indicating that tumor samples with the low-risk score may tend to have favorable responses to anticancer immunotherapies.