C9orf72 and amyotrophic lateral sclerosis: Having established benchmark physiological and maturation features of control OPCs and to assess the maturation profile of oligodendrocytes in a disease model we next derived oligodendroglia from hPSCs obtained from two ALS patients (iPSC91 and iPSC92) harboring mutations in the C9ORF72 gene (Fig. 7A).