PDCD1 and cancer: In the Gao et al. dataset, low–risk enriched more immune pathways, involving “Leukocyte transendothelial migration”, “PDL1 expression and PD1 checkpoint pathway in cancer”, “Th1 and Th2 cell differentiation”, “B cell receptor”, “Natural killer cell mediated cytotoxicity”, “Th17 cell differentiation”, and “T cell receptor”, and “Antigen processing and presentation” (Fig. 4).