Researchers at the University of Milan have published results indicating that adult neural stem cells might be used as a treatment for spinal muscular atrophy. This motor neuron disease is the second most common genetic disorder leading to death in childhood. Using a mouse model for the disease, the scientists injected neural stem cells into the spinal cords of animals. They found that treated mice showed improved muscular function and increased lifespan compared to untreated controls. While some of the transplanted cells developed into motor neurons, the major effect of the injected cells seems to be improving survival and function of existing motor neurons already present in the mice, suggesting that the adult stem cells secrete factors to assist survival and regeneration.