The strongly positive rates of NQO1 protein were significantly higher in Grade 2 (G2) (61.7%, 29/47) and Grade 3 (G3) (69.7%, 53/76) ovarian carcinomas than those in Grade 1 (G1) (27.0%, 10/37) cases (P = 0.000). The gene discussed is NQO1; the disease is ovarian carcinoma.