For example, TCF4 haploinsufficiency results in Pitt-Hopkins syndrome (MIM #610954) [17,18], a severe neurodevelopmental disorder, whereas somatic TCF4 mutations are commonly identified in Sonic hedgehog medulloblastoma [19] and common germline variants have been associated with Schizophrenia risk [20,21]. This evidence concerns the gene TCF4 and medulloblastoma.