Previously, we reported plasma NDE levels of Aβ42, P-tau-T181, P-tau-S396 increased while plasma NDE levels of NRGN decreased in MCI (mean age, 68.7 years) and AD (71.1 years) patients as compared to age-matched controls (mean age, 70.8 years) (Winston et al., 2016, 2019). The gene discussed is NRGN; the disease is Alzheimer disease.