KEGG pathway analysis revealed that the DEGs were mainly enriched in the IL-17 signaling pathway, rheumatoid arthritis, viral protein interaction with cytokines and cytokine receptors, the TNF signaling pathway, Salmonella infection, Kaposi sarcoma-associated herpesvirus infection, Legionellosis, the NF-kappa B signaling pathway, the AGE-RAGE signaling pathway in diabetic complications and cytokine-cytokine receptor interaction (Fig. 2B, Table 2). Here, TNF is linked to legionellosis.