Based on The Cancer Genome Atlas (TCGA) database (Gene Expression Profiling Interactive Analysis [GEPIA] platform), M2 macrophages with immunoregulatory properties were the most abundant immune cells infiltrating in common human tumors (colon, lung, and stomach adenocarcinomas; Supplemental Figure 2A) and possessed a preferential expression of Pdcd1 gene (Supplemental Figure 2B). This evidence concerns the gene PDCD1 and gastric adenocarcinoma.