VIPR2 and schizophrenia: Recently, genetic studies aimed at the discovery of copy number variants (CNVs) have revealed that microduplications of VIPR2 gene were strongly associated with schizophrenia (see below and Levinson et al., 2011; Vacic et al., 2011; Yuan et al., 2014; Li et al., 2016; Marshall et al., 2017).