ENPP1 and breast cancer: Here, we report that miR-27b inhibits the acquisition of CSC properties in luminal-type breast cancer and that metformin reduces the SP fraction of breast cancer cells through miR-27b-mediated repression of the gene ectonucleotide pyrophosphatase/phosphodiesterase family member 1 (ENPP1), which is involved in T2D development31.