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. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.