Generally, AD patients had significantly higher plasma levels of Aβ40 (p = 0.002), GFAP (p = 0.01), Nf–L (p = 0.04), and p-tau181 (p = 0.00005) than healthy individuals; however, Aβ42 and Aβ42/Aβ40 ratio did not differ between the two groups (p = 0.5) and (p = 0.06), respectively. Here, NEFL is linked to Alzheimer disease.