Consistent with the presence of upper motor neuron degeneration in ALS, there was marked accumulation of BRCA1-positive axonal swellings in the spinal cord corticospinal tract (laterodorsal funiculus) of ALS cases (Fig. 5h) that were not evident or very infrequent in age-matched control corticospinal tract axons (Fig. 5g). The gene discussed is BRCA1; the disease is amyotrophic lateral sclerosis.