SHH and medulloblastoma: These combined efforts resulted in a consensus at a recent conference in Boston in 2010, supporting the classification of medulloblastomas, based on the molecular profiling, into four clinical and molecular subtypes: the WNT subtype, in which the canonical WNT signaling is upregulated; the sonic hedgehog (SHH) subtype, with hallmark activation of the SHH-signaling cascade; and two additional groups called “group 3 (G3)” and “group 4 (G4)” medulloblastoma for which the specific signaling pathways leading to these two variants have not yet been conclusively determined [11].