Additionally, the accumulation of Poly(GP) in C9ORF72-associated ALS highlights the broader theme of misfolded proteins in ALS, with its presence serving as a biomarker for disease progression.27,34,42,90 Both Poly(GP) and cryptic peptides offer potential diagnostic and therapeutic targets, as monitoring their levels may provide insights into disease progression and treatment efficacy. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.