G4C2-repeat expansion of C9ORF72 is the most frequent genetic variant of ALS.52 We have previously developed a zebrafish model of C9ORF72-ALS which recapitulates key molecular and behavioural phenotypes of ALS including motor decline and early mortality.43 Diseased fish carry a transgene to express the C9ORF72 expansion fused inframe to GFP and in tandem, an hsp70-DsRed reporter for the activation of the heat shock cellular stress response (HSR). The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.