MMP1 and breast cancer: To determine whether miR-202-3p directly targets the 3’UTR of MMP1 mRNA in metastatic breast cancer cells, we conducted luciferase reporter assays by co-transfection of miR-202-3p mimic and luciferase constructs containing the putative (wild-type WT) or mutated (MUT) binding site of miR-202-3p in the 3′UTR of MMP1.