To confirm that the hepatic NPC1L1 could mediate reabsorption of biliary cholesterol into the liver of L1-Tg mice under HFD feeding, biliary secretion of cholesterol was investigated in each type of mice fed a HFD for 2 w (Fig. 1b), an enough period for steatosis formation in L1-Tg mice. Here, NPC1L1 is linked to steatosis.