CD8A and amyotrophic lateral sclerosis: Particularly, peripheral CD8+ T cell ablation has been shown to increase motoneuron survival in a mouse model of ALS, whereas in vitro studies showed that SOD-1 expressing CD8+ T lymphocytes recognize and selectively kill motoneurons via binding MHC-I molecules expressed on these cells, suggesting a possible autoimmune origin for ALS (159) (Figure 2).