Although many potentially toxic factors have emerged from studying the effects of ALS-CSF on glial cells, chitotriosidase-1 (CHIT-1), an inflammatory product specific to microglia, has been proposed to play a particularly important role in CSF-mediated neurodegeneration (Varghese et al., 2020). This evidence concerns the gene CHIT1 and amyotrophic lateral sclerosis.