NQO2 (EC 1.10.99.2) is a flavoprotein that catalyzes the 2-electron reduction of various quinones, redox dyes, and the vitamin K menadione. NQO2 predominantly uses dihydronicotinamide riboside (NRH) as the electron donor (summary by Wu et al., 1997 [PubMed 9367528]).[supplied by OMIM, Jul 2010]