PPARA and asthma: In addition, the following important metabolic pathways were identified: linoleic acid metabolism, arachidonic acid metabolism, neuroactive ligand–receptor interaction, serotonergic synapse, PPAR signaling pathway, Fc epsilon RI signaling pathway, sphingolipid metabolism, asthma, steroid biosynthesis, primary bile acid biosynthesis, necroptosis, chemical carcinogenesis, and the metabolism of xenobiotics by cytochrome P450 (Figure 7B).