ABCB1 and ovarian cancer: There is also growing evidence that treatment of cancer cells with HA upregulates the expression of the multidrug transporter, MDR1 (P-glycoprotein), and ABC drug transporters (ABCB3, ABCC1, ABCC2, and ABCC3) leading to aberrant drug fluxes and chemoresistance in breast and ovarian cancer cells (39, 40).