“…In humans, 49 ABC genes organized into seven subfamilies (A-G) have been described (Dean and Annilo, 2005;Lončar et al, 2010). Despite the large number of ABC proteins, previous studies have revealed that the P-glycoprotein (ABCB1), the Bile Salt Export Pump (BSEP; ABCB11), the multidrug resistanceassociated proteins 1-5 (ABCC1-5), and the breast cancer resistance protein (ABCG2) are the most toxicologically relevant proteins in mammals (Leslie et al, 2005;Szakacs et al, 2008). Though there is some overlap in the substrate specificity of these ABC transporters, there are differences in their transport mechanisms (Costa et al, 2012).…”