Studies with mice null for the GPBAR1 receptor suggest that it has a role in macrophage activation in vivo; GPBAR1−/− mice treated with LPS had abundant macrophage infiltration into the liver and enhanced liver pathology compared to wild-type controls [12] and GPBAR1−/− mice also had more severe injury-induced colitis than wild-type controls [13]. Here, GPBAR1 is linked to colitis.