SOD1 and amyotrophic lateral sclerosis: Astrocytes are increasingly recognized as playing fundamental roles in ALS pathogenesis.11 Ourselves and others have previously used human stem cell models to demonstrate non-cell-autonomous mechanisms of disease mediated by SOD1-mutant astrocytes in ALS.9 Additionally, we have reported a VCP mutant astrocyte survival phenotype compared to control counterparts.12 Against this background, we sought to address whether human induced pluripotent stem cell (hiPSC)-derived ALS astrocytes could undergo deleterious reactive transformation cell autonomously.