HMGA2, an architectural transcription factor, is abundant in tumor cells and its high expression is related to poor survival rates in many types of cancers including breast cancer, colorectal cancer or lung cancer.18, 19, 20, 21, 22 Yet, the role of HMGA2 in metformin‐mediated breast cancer inhibition is as yet undetermined. Here, HMGA2 is linked to breast cancer.