NQO1 and cancer: Among the genes found down-regulated in the specimens obtained from lymph node positive patients, the NQO1 gene encodes the phase II drug-metabolizing enzyme NAD(P)H:quinine oxidoreductase 1 (NQO1) and is considered significant for susceptibility to general carcinogenesis, and the genomic mutation in NQO1 is frequently found in cancer of colon, bladder, lung and pediatric leukemia.