DNMT3A and amyotrophic lateral sclerosis: While healthy control cell lines show a twofold upregulation of DNMT1, 2 and 3a during differentiation in average, ALS cell lines show 40 fold upregulation of DNMT1 during differentiation from NPCs to MNs, 16 fold upregulation of DNTM2 and three fold upregulation of DNMT3a.