NR1H4 and cholestasis: We previously reported that IL-1β-mediated suppression of FXR signaling was a key factor in the pathogenesis of cholestasis in the PNAC mouse model.6,7,36 To determine the role of IL-1β in activation of the IL-6-STAT3 pathway in the liver, we treated WT mice with i.p. injection of IL-1β and exposed cultured primary mouse hepatocytes and HepG2 cells to IL-1β overnight and measured Il-6 mRNA expression.