TCF4 and schizophrenia: Furthermore, several TCF4 binding sites are also located within the TCF4 gene itself suggesting that TCF4 may autoregulate the expression of its numerous distinct isoforms.24 In addition to the common variant schizophrenia risk loci, rare LoF mutations in SETD1A have recently been associated with schizophrenia and developmental disorders.49,50SETD1A, that encodes a histone methyltransferase, has a TCF4 binding site (chr16:30968306–30969367) at its TSS, potentially implicating both schizophrenia risk genes in the same regulatory network.