This study presents comprehensive analysis of the significance of antioxidant gene polymorphisms (Nrf2 rs6721961, KEAP1 rs1048290, GSTP1AB rs1695, GSTP1CD rs1138272, GPX3 rs8177412 and MDR1 rs1045642) in BEN development and associated urothelial cell carcinoma. This evidence concerns the gene KEAP1 and Balkan nephropathy.