Further, post-mortem samples from ALS patients harboring C9orf72 mutations demonstrated that RNA foci sequester hnRNP H/F (Cooper-Knock et al., 2014); hnRNP H/F is necessary for PLP/DM20 alternative splicing (Wang et al., 2007, 2008), a process critical for normal myelination. Here, HNRNPH2 is linked to amyotrophic lateral sclerosis.