Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that causes the progressive loss of both upper and lower motor neurons in the brain, brainstem, and spinal cord. The exact mechanisms of ALS are still unclear, but genetic and molecular studies have revealed some key factors that may contribute to motor neuron death. Besides motor neurons, other cell types in the nervous system, such as reactive astrocytes and activated microglia, also show pathological changes and secrete harmful substances and inflammatory cytokines (Appel et al., 2011).