The Sonic hedgehog (SHH) subgroup of medulloblastoma, which accounts for 30% of all medulloblastoma cases, is believed to originate from the cerebellar granule neuron progenitor (CGNP) population that critically depends on SHH pathway signaling for its perinatal expansion (Dahmane and Ruiz, 1999; Hovestadt et al., 2019; Salsano et al., 2004; Vladoiu et al., 2019; Wallace, 1999; Wechsler-Reya and Scott, 1999; Yang et al., 2008; Yokota et al., 1996). This evidence concerns the gene SHH and medulloblastoma.