NQO1 and ulcerative colitis: Kosaka et al. [5] by examining manganese superoxide dismutase SOD2 Ala-9Val and NAD(P)H:quinone oxidoreductase 1 NQO1 C609T gene polymorphisms have found that SOD2 Ala-9Val genetic variations may influence on age of onset of ulcerative colitis while the NQO1 C609T polymorphism may affect on severity of UC and steroid resistance in patients.