In the present study, we have comparatively examined the effects of 17-AAG-induced Hsp90 inhibition on multiple protein targets implicated in signaling pathways critically regulating cell proliferation, apoptosis and motility, in RT4 (grade I), RT112 (grade I-II) and T24 (grade III) human urothelial bladder cancer cells. This evidence concerns the gene HSP90AB1 and bladder transitional cell carcinoma.