In line with this hypothesis direct intracranial AAV-ASPA gene delivery to CNS neurons showed limited therapeutic benefit [2, 3, 40], while in a recent study neonatal delivery of a novel AAV serotype that preferably infects oligodendrocytes prevented development of CD in ASPAnur7/nur7 mice, at least until three months of age [25]. This evidence concerns the gene ASPA and Cowden disease.