GPBAR1 and colitis: Because the data support the notion that regulation of ACE2 expression in the colon is regulated by GPBAR1 but the effect of Gpbar1 gene ablation is obscured by the fact that Gpbar1−/− mice develop a severe inflammation, we further dissected these signaling pathways by challenging wild type mice with colitis induced by administration of oxazolone with BAR501, a potent GPBAR1 agonist, which effectively regulates intestinal inflammation in Gpbar1-dependent manner [23].