PDCD1 and cancer: In terms of immune-related pathways, DEGs between immunity-high and -low abundance groups of immune cell infiltration were enriched in multiple immune-related pathways according to GO and KEGG analyses; for example, PD-L1 expression and PD-1 checkpoint pathway in cancer, antigen processing and presentation, Fc gamma R-mediated phagocytosis, T-cell receptor signaling pathway, and natural killer cell-mediated cytotoxicity.