Considering the fact that, and until the date of this paper, there are no prior studies assessing the expression of CYP4Z1 and CYP1B1 in bladder cancers, this study aims to examine the aberrant expression of CYP4Z1 and CYP1B1 in different subtypes of bladder cancer and correlate their expressions with baseline demographic and clinicopathologic features. The gene discussed is CYP4Z1; the disease is urinary bladder cancer.