That absolute NfL levels were low is also evident when comparing the mean plasma NfL values in our high and low NfL groups (11.5 pg/mL and 6.7 pg/mL, respectively) to the mean plasma NfL levels that were reported in participants of the ADNI cohort that had dementia (45.9 pg/mL) or mild cognitive impairment (37.9 pg/mL)(Mattsson et al., 2019). Here, NEFL is linked to Cognitive impairment.