PDCD1 and cancer: The CAFDL signature was significantly positively associated with TGFB1, CD276, CD40, VEGFA, VEGFB, etc., but showed significantly negative correlation with immune checkpoints (such as CD274, PDCD1, CTLA4, TIGHT, and HAVCR2) and anti-cancer immune regulators (IFNG, IDO1, and GZMA) (Figure 7B).