Nonetheless, ABCB1 and ABCG2 are heavily expressed at the apical surface of the intestinal wall, which is therefore likely to be the major cite where orally administered tenofovir disoproxil fumarate could encounter these transporters. Therefore, it may well be that tenofovir plasma concentrations, and therefore the extent of tenofovir-exposure-associated nephrotoxicity, are influenced by the actions of these transporters on tenofovir disoproxil fumarate absorption. The efflux transporter ABCC10 is known to confer resistance to several anti-cancer drugs