Consistent with the previous study showing impaired mitochondrial transport in ALS (Sasaki and Iwata, 1996), COX-1 immunoreactive mitochondria were only present in soma and depleted in the neurites of spinal cord motor neurons of ALS patients, compared to the uniform distribution of Cox-1 throughout the soma and neurites of age-matched control motor neurons (Figure 1B). This evidence concerns the gene MT-CO1 and amyotrophic lateral sclerosis.