Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease leading to selective death of upper and lower motoneurons. Clinically, the ALS syndrome is linked to pathogenic mutations in superoxide dismutase 1 (SOD1), though actual molecular mechanisms remain ill understood. Two papers recently published in Cell Stem Cell and Cell Reports employ syngenic, iPSC-derived cell lines of one of the most severe SOD1 mutations to report mitochondrial and ER stress as causal for perturbed electrical activity in ALS neurons (Kiskinis et al, 2014; Wainger et al, 2014).