PFKL and amyotrophic lateral sclerosis: Humans have three isoforms of PFK, namely PFKM, PFKL, and PFKP. Although all are present in the brain, PFKL is expressed at lower levels (Human Brain Transcriptome: http://hbatlas.org/) thus we focused on PFKP and PFKM. For human tissues we used spinal cords isolated from ALS patients with TDP-43 proteinopathy and controls lacking neurological defects (see Supplementary file 2 for demographic information).