The prognostic genes of six (BRCA, CESC, HNSC, LUAD, SARC, and LGG) out of the 22 cancer types were significantly enriched in ≥5 immune system-related pathways (chemokine signaling pathway, complement and coagulation cascades, antigen processing and presentation, hematopoietic cell lineage, natural killer cell-mediated cytotoxicity, Th1 and Th2 cell differentiation, Th17 cell differentiation, TCR signaling pathway and intestinal immune network for IgA production), which are presented in Fig. 1. This evidence concerns the gene CD79A and cancer.