PDCD1 and cancer: The results showed that regulation of these proteins was involved in some immune-related pathways such as Th17 cell differentiation (FDR = 6.40 × 10−7), PD-L1 expression and the PD-1 checkpoint pathway in cancer (FDR = 9.88 × 10−6), B-cell receptor signaling pathway (FDR = 0.00022), Th1 and Th2 cell differentiation (FDR = 0.00028), and T-cell receptor signaling pathway (FDR = 0.00037) (Table 3).