APOB and amyotrophic lateral sclerosis: By performing CSF filtration studies to systematically eliminate components by molecular weight and unbiased global proteome profiling of sALS CSF pre- and post-filtration, we identified apolipoprotein B-100 (ApoB) as the neurotoxic agent responsible for inducing motor disability, motor neuron death, and other hallmark ALS pathology in the spinal cord.