PGP and ovarian cancer: The results from many clinical trials showed almost no survival benefits by using these MDR reversing agents of Pgp inhibitors such as verapamil, cyclosporine-A, PSC-833 (Valspodar) and VX-710 (Biricodar) in different cancer types including ovarian cancer, highlighting a crucial need for an alternative specific, safe and effective strategy to overcome MDR36, 37, 38, 39, 40.