Genetic polymorphisms or dysregulation of NCAM (Arai et al., 2004; Atz et al., 2007; Anney et al., 2010; Gray et al., 2010; Varea et al., 2012) and ephrinA/EphA (Wilson et al., 2006; Ikeda et al., 2010; Ayalew et al., 2012; Casey et al., 2012) have been linked to schizophrenia, autism and bipolar disorder. The gene discussed is NCAM1; the disease is schizophrenia.