Altogether, due to the numerous trophic effects described for neurotrophins in motoneurons, and considering that, first, extraocular motoneurons and muscles are enriched in these molecules in contrast to other cranial motor systems, and, second, that extraocular motoneurons are less vulnerable to ALS, we suggest that the high presence of neurotrophins in the extraoculomotor system might be linked to their higher resistance to this disease. The gene discussed is BDNF; the disease is amyotrophic lateral sclerosis.