Collectively, restoration of miRNA-34a-5p increases the sensitivity of the drug-resistant breast cancer cells via direct inhibition of the ABCC1 gene which is confirmed to has a role not only in mediating chemotherapeutic drugs exportation, but also in transporting a variety of substrates involved in inflammation and cellular signaling and proved in several different types of cancer to have a role in proliferation, clonogenic capacity, cell migration, and invasion, such as bioactive lipids sphingosine-1-phosphate, and lysophosphatidyl inositol [53]. This evidence concerns the gene ABCC1 and breast cancer.