In another study, subjects were grouped on the basis of antemortem behavioural testing and postmortem histopathological assessment as no cognitive impairment (NCI), preclinical AD, mild cognitive impairment (MCI), and early to moderate AD; NOX activity was measured luminometrically, and protein expression levels of NOX2 subunits were assessed by immunoblotting [133]. This evidence concerns the gene CYBB and Alzheimer disease.