Furthermore, GPR116Ad−/− mice exhibited mild pre-diabetes symptoms, such as compensatory hyperinsulinemia compared to GPR116Adf/f littermates, but these phenotypes were milder compared to those observed upon deletion of GPR116 under the control of the Ap2 promoter (Ap2CreGPR116−/− mouse). The gene discussed is ADGRF5; the disease is hyperinsulinism.