Previous investigations in small numbers of patients with unselected clinical blood samples (i.e. without known neurodegenerative diagnosis, n = 30) or amyotrophic lateral sclerosis (n = 22 patients) suggest good correlations between venous blood DPS and plasma NfL (R2 = 0.9511,12 and R2 = 0.911,12). Here, NEFL is linked to amyotrophic lateral sclerosis.