In particular, NQO1, which encodes the superoxide scavenger NAD(P)H dehydrogenase (quinone 1), SOD2, which converts O2•– into H2O2 and catalase (CAT), which eliminates H2O2, were increased in individuals with NAFL or NASH with mild fibrosis, but tended to decline in individuals with NASH with significant/advanced fibrosis. This evidence concerns the gene SOD2 and non-alcoholic fatty liver.