Defined as an embryonal CNS tumor, medulloblastoma is thought to arise from disruptions during the development of cerebellum as a result of dysregulated genes and pathways, including the Notch, WNT/β-Catenin, Transforming growth factor-beta (TGF-β)/bone morphogenetic protein (BMP), SHH/Patched, and Hippo pathways (Roussel and Hatten, 2011) in embryonic development. The gene discussed is SHH; the disease is medulloblastoma.