NQO1 is a cytosolic antioxidant flavoprotein that catalyzes the reduction of highly reactive quinone metabolites and their derivatives by using NAD(P)H as an electron donor. Thus NQO1 acts as a detoxyfying enzyme and is involved in the body's protection against oxidative stress. NQO1 acts as a protein chaperone, one of its targets being p53. In humans NQO1 is expressed at high levels in adipocytes and its expression levels are positively correlated with adiposity, glucose tolerance, and makers of liver dysfunction. Altered expression of NQO1 is associated with Alzheimer's disease. NQO1 is abnormally elevated in many types of solid tumors and may represent a useful biomarker of pancreatic cancer.