Although, the expression of pathogenic GGGGCC repeat expansions in zebrafish result in RNA foci and DPR formation that are toxicity as in ALS, perhaps the best approach to accurately model C9orf72-related ALS in zebrafish, is to attempt knock-in the repeats in intron 1 of the zebrafish c9orf72 with CRISPR genome editing approaches in the future. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.