ABCC1 and breast cancer: Further study, we proved miR-145 sensitized breast cancer cells to doxorubicin via inducing intracellular doxorubicin accumulation by inhibiting MRP1, synthetic or stably expressed miR-145 reversed resistance to doxorubicin in vitro and in vivo by targeting MRP1, miR-145 exerts the potential to be developed for MDR inhibitors (Figure 4 and 5).