SMPD1 and lysosomal storage disease: Genetically engineered neural progenitor and stem cells expressing acid sphingomyelinase have been reported to reverse lysosomal storage pathology in animal models of Niemann-Pick’s disease (Shihabuddin et al. 2004), confirming the potential of NSCs to serve as a gene transfer vehicle for the treatment of CNS pathology, particularly for lysosomal storage diseases.