At T1, percentages of β3tubulin-positive neurons expressing the VACHT marker were similar between control and ALS iPSC-derived MNs (all controls: 97.4 ± 1.1%; SOD1: 98.3 ± 1.75%; C9orf72: 94.8 ± 2.5%; TARDBP: 98.8 ± 1.4% (mean ± SEM)) (Fig. 1f). This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.