Moreover, single nucleotide variants (SNVs) in NRG and ERBB genes have been associated with an increased risk of psychiatric conditions such as schizophrenia and bipolar disorder (Mei and Nave, 2014), analogous to findings reported for Teneurin-4 (Psychiatric GWAS Consortium Bipolar Disorder Working Group, 2011; Ivorra et al., 2014). This evidence concerns the gene TENM4 and schizophrenia.