To detect the difference in expression of BMP9 in bladder cancer and normal bladder tissues, 256 cases of bladder mucosa specimens (68 cases of superficial bladder cancer (T, Ta, Tis), 62 cases of infiltrating bladder cancer (T1–T4) and 126 cases of normal bladder) in the Lee Bladder database on Oncomine (available online: www.oncomine.org) were used for sequence alignment analysis. Here, GDF2 is linked to urinary bladder cancer.