CAMP and legionellosis: KEGG enrichment analysis showed that compared with Group C, the up-regulated DEGs in Group M were enriched in immune-related pathways such as cytokine-cytokine receptor interaction, the IL-17 signaling pathway, the CAMP signaling pathway, and were involved in chemical carcinogenesis-DNA adducts, drug metabolism, Lipid and atherosclerosis, linoleic acid metabolism, and Legionellosis (Figure 7A); the down-regulated DEGs are also enriched in drug metabolism, in addition to the PI3K-Akt signaling pathway, cell cycle, cardiomyopathy, cancer, and other related pathways (Figure 7B).