Previous studies showed that metformin can selectively targets BCSCs and suppress breast tumour growth.21, 25, 26 In addition, CD47 has been reported to show different expression levels in the development of type II diabetes mellitus.27 Then we hypothesized that metformin may attenuate the BCSCs through miR‐708‐mediated suppression of CD47. The gene discussed is CD47; the disease is breast neoplasm.