MUC5AC and type 2 diabetes mellitus: In contrast, among the 51 downregulated genes, five metabolic pathways, including neuroactive ligand–receptor interaction (hsa04080), renin–angiotensin system (hsa04614), maturity-onset diabetes of the young (hsa04950), nicotinate and nicotinamide metabolism (hsa00760), and mucin-type O-glycan biosynthesis (hsa00512) were significantly enriched (Table S6).