ABCB4 and cholestasis: For example, dysregulation or mutations in genes encoding for bile salt export pump (BSEP), multidrug resistance protein 3 (MDR3) [6], or cholesterol 7a-hydroxylase (CYP7A1) [7] and bile acid-CoA:amino acid N-acyltransferease (BAAT) can evoke cholestasis [8].