MPO and colitis: Contrary to these results, Kimet al. in 2013 reported that pharmacologic blockade or genetic ablation of 5-HT7R actually alleviated intestinal inflammation in two separate chemical models of colitis (DSS and DNBS), which was confirmed histopathologically and also associated with decreased concentrations of pro-inflammatory markers, including myeloperoxidase (MPO) and cytokines IL-1β, IL-6, and TNF-α.