These findings are consistent with earlier studies that have demonstrated TCF4 expression in human or rodent nervous system [18], [40]–[44] and further support the important role for TCF4 in the development and functioning of the nervous system as exemplified by involvement of TCF4 in the pontine nucleus development in mice, association of TCF4 with schizophrenia and identification of TCF4 haploinsufficiency as the cause of Pitt-Hopkins mental retardation syndrome [17], [21]–[24]. This evidence concerns the gene TCF4 and schizophrenia.