ALS is a universally fatal neurodegenerative condition that causes weakness leading to paralysis and death. Life expectancy is 2-5 years. The cause is unknown and there is no effective treatment. Previous research has shown that on autopsy, ALS patients are found to have increased levels of the amino acid glutamate accumulated in the brain and spinal cord. This increase is thought to be caused by a decrease in the glutamate transporter which normally "cleans up" glutamate from the cells. HSSC are known to express amino acid transporters and it is hoped that this action will reduce the toxicity of accumulated glutamate and benefit ALS patients. There is a second hypothesized benefit of the HSSC and that is their ability to secrete neurotrophic support factors. Neurotrophic factors support the health of nerves.