To clarify the role of NDRG1 in the growth of bladder cancer cells, 5637 cells treated with pcDNA3.1-NDRG1 or NDRG1 siRNAs were examined by a CCK-8 assay and an Annexin V-FITC/PI kit (Fig. 4). Here, NDRG1 is linked to urinary bladder cancer.