PD-L1 mRNA expression levels are correlated the expression levels of IFNG, JAK2 and STAT1. (A) Kyoto Encyclopedia of Genes and Genomes analysis revealed nine genes that were enriched in the JAK/STAT signaling pathway. Spearman's rank correlation analysis between the mRNA expression levels of (B) PD-L1 and IFNG, (C) PD-L1 and JAK2 and (D) PD-L1 and STAT1. PD-L1, programmed death ligand 1; JAK, janus kinase; GF, galphaf; STAM, signal transducing adaptor molecule; TC-PTP, protein tyrosine phosphatase non-receptor; SHP1, the protein-tyrosine phosphatase Shp1; SHP2, the protein-tyrosine phosphatase SHP2; GRB, growth factor receptor; IRF9, interferon regulatory factor 9; GRB, growth factor receptor bound protein; SOS, SOS Ras/Rac guanine nucleotide exchange factor.