Using both transgenic mouse and rat SOD1-linked familial ALS (FALS) models, we found that AAK1 was partially colocalized with the endosomal and presynaptic protein markers under the normal physiological condition, but was mislocated into aggregates that contained mutant SOD1s and the neurofilament proteins in rodent models of ALS in disease. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.