Discrepancies between our findings and those from the Irwin group, may result from differences in inclusion criteria; whereas participants with ALS or FTLD-TDP type B were included in the Irwin study [42], they were excluded from our study given that TDP-43 type B is associated with FTD-ALS phenotypes [35], and participants with ALS have significantly higher plasma NfL than participants with FTD, which may confound our analyses [5]. Here, NEFL is linked to amyotrophic lateral sclerosis.