Animal studies
Harvest of cerebellar granule neuron precursors from neonatal mice, preparation of cerebella and tumor tissue from wild-type and mutant mice for histological analysis, and irradiation of tumor-bearing mice were carried out in compliance with the Memorial Sloan-Kettering Institutional animal care and use committee guidelines. NeuroD2-SmoA1 mice were provided by Jim Olson (Fred Hutchinson Cancer Research Center). Patched+/− mice were provided by Kathryn Anderson (Memorial Sloan-Kettering Cancer Center). NOD/SCID mice were purchased from The Jackson Laboratory.