4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) metabolism-related enzymes gene polymorphisms, NNK metabolites levels and urothelial carcinoma

► Significant dose-response associations between NNK-related metabolites and UC risk. ► Subjects with the UGT2B7 codon 268 His/Tyr or Tyr/Tyr genotype had lower total NNAL. ► No association was seen between gene polymorphisms of CYP2A13 and UGT2B7 and UC risk.