Because incubation with TGFβ1 resulted in increasing miR-221 levels in both RT4 and T24 cells, we silenced miR-221 to test whether miR-221 is involved in motility changes in bladder cancer cells, aiming to examine the specific role of miR-221 in TGFβ1-induced EMT. Here, TGFB1 is linked to urinary bladder cancer.