Further, gdf6a−/− fish at nine months of age were noted to have approximately 50% fewer spinal motoneurons compared to wildtype fish (p<0.001, Figure 3, n>50 sections from 4 fish per genotype), akin to changes observed in ALS model fish overexpressing mutant SOD1 [28]. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.