SHH and embryonal neoplasm: Medulloblastoma, an aggressive embryonal tumor arising in the cerebellum or, less frequently, in the dorsal brain stem, is one of the most common malignant central nervous system tumors in children.1 Four clinically relevant molecular subgroups—WNT (wingless-related integration site), SHH (sonic hedgehog signaling molecule), group 3, and group 4—are known2 and have been differentiated into additional subtypes.3,4,5 Unfortunately, identification of these subgroups has not yet translated into more effective targeted therapies.