The similarity of the anticholestatic effect of tropifexor and OCA in PBC as well as the similarity in the side effects around itch and lipids demonstrated that these effects pertain to FXR agonists as a class of drugs and are not caused by alternative biological actions, given the bile acid structure of OCA vs. the non-bile acid structure of tropifexor. Here, NR1H4 is linked to primary biliary cholangitis.