ATP8B1 and progressive familial intrahepatic cholestasis: Two different forms of inherited cholestasis, benign recurrent intrahepatic cholestasis (BRIC) and progressive familial intrahepatic cholestasis (PFIC1) were correlated with mutations in ATP8B1 (FIC1), in chromosome 18 [15], a membrane protein that activates FXR via protein kinase C-zeta, and mutations in FIC1 are associated with downstream effects of FXR on BA homeostasis [16].