GPBAR1 and cholestasis: However, a recent study found that administering TGR5-selective agonists failed to elicit an itch response in mouse models of cholestasis (Cipriani et al., 2015), and TGR5-specific agonists in recent clinical trials have not been reported to have itch side effect (Hodge et al., 2013), raising doubts regarding whether TGR5 is indeed the principal mediator for cholestatic itch.