A number of studies have focused on the coding region or missense variants that enhance CYP1B1 catalytic activity and show them to be associated with prostate cancer.27, 28 Also of importance are variants in the promoter or 5′ untranslated region (5′UTR) as these may lead to an up‐regulation29 or down‐regulation30 of RNA transcription and consequentially, enzyme expression levels. The gene discussed is CYP1B1; the disease is prostate cancer.