PDCD1 and cancer: For instance, immunotherapies such as adoptive transfer of chimeric antigen receptor T cells or autologous tumor-infiltrating T cells [91,92]; antibodies targeting immune checkpoint mediators, including programmed cell death 1 (PD1), PD ligand 1 (PD-L1), or cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) [93,94,95]; and cancer-specific peptide vaccine-based immunotherapies [96,97,98] have shown promising antitumor activities in humanized or preclinical cancer models.