MUC5AC and legionellosis: The downregulated DEGs were principally related to complement and coagulation cascades, fatty acid biosynthesis, legionellosis, mucin‐type O‐glycan biosynthesis, nitrogen metabolism, pantothenate and CoA biosynthesis, PPAR signaling pathway, starch and sucrose metabolism, ubiquinone, and other terpenoid‐quinone biosynthesis (Figure 1f).