Using a cell model derived from biopsies of the olfactory mucosa termed, human olfactory neurosphere-derived cells (hONS), it has been observed that a significant alteration of “Nrf2-dependent antioxidant response pathway” was associated to reduced levels of glutathione and salt, a measure of cellular metabolic activity based on reduction by NAD(P)H-dependent dehydrogenase enzymes in PD patient-derived hONS cell lines when compared with control-donor derived cells (Matigian et al., 2010). The gene discussed is NFE2L2; the disease is Parkinson disease.