Most, if not all, derivation protocols used thus far to generate astrocytes for ALS modeling have started from NPCs exposed to RA and SHH agonists (e.g., Hall et al., 2017; Qian et al., 2017; Kelley et al., 2018b; Birger et al., 2019; Varcianna et al., 2019; Zhao et al., 2020), suggesting that they likely gave rise to astrocytes with spinal features. Here, SHH is linked to amyotrophic lateral sclerosis.