Heterogenous population with schizophrenia revealed genetic component as a critical factor associated with disease and many other genes, including catechol-O-methyl transferase (COMT), dysbindin (DTNBP1), a regulator of G-protein signaling 4 (RGS4), disrupted-in-schizophrenia 1 (DISC1), and metabotropic glutamate receptor 3 (GRM3, also known as MGLUR3) and neuregulin1 and its receptor ERbB4 are linked to schizophrenia [509,512,513]. The gene discussed is GRM3; the disease is schizophrenia.