Downregulated genes included: Unc13a, which is involved in neurotransmitter release via vesicle maturation and has been implicated in ALS (Dittman, 2019; Diekstra et al., 2014), and Vgf, a secreted growth factor whose expression is also decreased in PD (Quinn et al., 2021). Here, VGF is linked to amyotrophic lateral sclerosis.