Aside from the healthy donor derived SIGi001-A-20 iSOX9-astrocytes, we also included early and late iSOX9-astrocytes from an ALS patient-derived iPSC line (as described in Guo et al., [48]), genome-engineered in the same way to allow forced expression of SOX9. We also included commercially available iPSC-derived astrocytes (“iCell” astrocytes) and fHA. This evidence concerns the gene SOX9 and amyotrophic lateral sclerosis.