CCR2 and cholestasis: The critical role of hepatic macrophages was demonstrated by the pharmacological blockage of the IL-1β receptor (by anakinra) or genetic deficiency of C-C motif chemokine receptor (CCR2), both of which prevented cholestasis.34The critical role of phytosterols was demonstrated in PN-fed mice, which did not develop PNAC when receiving FO-LE; however, when FO-LE was spiked with the phytosterol stigmasterol, hepatic macrophage activation, downregulation of canalicular transporters, and biochemical evidence of cholestasis were all observed.31