CHL1 and amyotrophic lateral sclerosis: Vulnerable spinal MNs showed an upregulation of a gene set known to be important for nerve regeneration, including Gap43, Cd44, Chl1, Atf3, Sprr1a, and Adcyap1. This highlights that vulnerable MNs during ALS are actively trying to overcome the ongoing degeneration by inducing genes that stimulate regeneration.