IL17A and rheumatoid arthritis: As shown in Figure 3(a), these genes from module A mainly are involved in four pathways that were NF-kappa B signaling pathway, chemokine signaling pathway, legionellosis signaling pathway (with Salmonella infection, interleukin 17 (IL-17), tumor necrosis factor (TNF), epithelial cell, and rheumatoid arthritis (RA) signaling pathway as subgroups), and Staphylococcus aureus infection signaling pathway.