In our study, we observed that miR-671-5p transfected MDA-MB-231 cells showed an epithelioid appearance and expressed epithelial cell marker E-cadherin, while mock transfected cells displayed elongated, irregular fibroblastoid morphology and expressed typical mesenchymal marker vimentin, suggesting a tumor suppressive effect of miR-671-5p in EMT. The gene discussed is VIM; the disease is neoplasm.