ABCC1 and cancer: miR-134 sensitizes cancer cells to chemotherapy by various mechanisms.12, 45, 46 miR-134 sensitizes MCF-7/ADR cells to doxorubicin by downregulating ABCC1.45 It also enhances the sensitivity of SKOV3-TR30 cells to paclitaxel by targeting Pak2 and promoting apoptosis.46 However, miR-134 overexpression confers resistance to the EGFR inhibitor gefitinib.11 In the current study, we found that miR-134 was upregulated in the adriamycin-resistant human ovarian cell line SKOV3(R) compared with the parental SKOV3 cell line.