We determined that miR-96 likely promotes breast cancer proliferation by directly targeting the 3′untranslated region (3′-UTR) of the FOXO3a mRNA, consequently reducing the expression of cyclin-dependent kinase (CDK) inhibitors, p27Kip1 and p21Cip1, and upregulating the cell-cycle regulator cyclin D1. Here, CCND1 is linked to breast cancer.