WT1 knockdown in HCT116 cells. After 12 or 24 h of transfection, the WT1 and Bcl-2 protein expressions were analyzed by western blotting. WT1, Wilms' tumor protein; Bcl-2, B-cell lymphoma-2; siRNA, small interfering RNA; N, non-transfected; C, control scrambled siRNA; W, WT1-targetinng siRNA.