Though there are as yet—to our knowledge—no published data on plasma NfL in trials of AD DMTs, decreases in plasma NfL levels have been shown to parallel clinical improvement in other neurological diseases, including in spinal muscular atrophy and multiple sclerosis (Kuhle et al, 2019; Olsson et al, 2019), where effective DMTs exist. This evidence concerns the gene NEFL and spinal muscular atrophy.