Most medulloblastomas are thought to originate from cerebellar granule neuron precursors (CGNPs) [4], and several signaling pathways have been implicated in medulloblastoma formation including aberrant activation of WNT, sonic hedgehog (Shh), and epidermal growth factor receptor (EGFR) signaling cascades. The gene discussed is SHH; the disease is medulloblastoma.