47 proved that HMGA2 expression was positively correlated with tumor histological grade, and it was important with pathogenesis of breast cancer. Therefore, HMGA2 is becoming recognized as a key mediator in numerous mesenchymal and epithelial malignancies. In the current study, we substantiated that HMGA2 was negatively regulated by miR‐20a‐5p and exerted a certain influence on BC cell growth, cell mobility, invasiveness, and apoptosis. The gene discussed is HMGA2; the disease is breast cancer.