PGP and hepatocellular carcinoma: In the present study, we found that miR-338-5p could suppress the expression of ABCB1, a drug transporter and the main reason for MDR, and sensitize HCC cells to doxorubicin (DOX) and vinblastine (VBL), two chemotherapeutic drugs and P-gp (P-glycoprotein) substrates.