Geldanamycin proved the first natural product carrying Hsp90 inhibitory properties that was able to critically interfere with a complex network of oncogenic signaling pathways regulating survival, proliferation and motility of the two -representative for the disease- human urinary bladder cancer cell lines, of diverse malignancy grade and p53 genetic content, RT4 (grade I; wild-type p53) and T24 (grade III; mutant p53). The gene discussed is HSP90AB1; the disease is urinary bladder cancer.