NQO1 and metabolic syndrome: Apn has been reported to activate the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, thereby increasing the expression of downstream proteins such as heme oxygenase 1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1), which prevents oxidative stress-induced DNA damage and metabolic syndrome [9,10].