As for the categorization of an ALS cerebellum sample to a specific ALS subtype (sporadic ALS or C9orf72-related ALS), the topmost determinative genes were C9orf72 and PRDM13. C9orf72 is widely accepted as the most common genetic cause of amyotrophic lateral sclerosis (Yang et al. 2020), while the PRDM13 gene, although not yet related to ALS, plays a major role in neuron differentiation and maintenance by encoding a transcriptional repressor (Bessodes et al. 2017; Leszczyński et al. 2020). This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.