CX3CR1 and amyotrophic lateral sclerosis: Four known ALS-associated genes (HSPB1, CAV1, CX3CR1, RNASE2) were among the informative genes selected for the cluster signatures, with all four demonstrating significant differences in their average expression values between clusters when performing one-way ANCOVA corrected for sex assigned at birth, age at death and post-mortem delay (Supplementary Fig. 3).