Recent reports have shown the importance of microRNA-200 (miR-200) family downregulation during EMT (2, 12, 21, 36); however, the functions of upregulated miRNAs during TGF-??-induced EMT remain uncharacterized.miRNAs are a class of 22-nucleotide noncoding RNAs that are evolutionarily conserved and function as negative regulators of gene expression.