CP-100356 is a specific inhibitor of MDR1 (P-Gp), the protypical ABC transporter. CP-100356 also inhibits prazosin transport in human breast cancer resistance protein (BCRP)-transfected MDCKII cells, suggesting that it acts as a dual inhibitor. CP-100356 does not inhibit multidrug resistance-associated protein 2 (MPR2 IC50 >15 mM).
