In contrast, Rollison et al. concluded that BK virus did not play a major role in the pathogenesis of bladder carcinoma, as only 5.5 % of the bladder cancer samples of 76 patients with urothelial carcinoma were BK positive by polymerase chain reaction (PCR) and none of them showed TAg expression. The gene discussed is KNG1; the disease is urinary bladder carcinoma.