Abstract: The present invention generally relates to the field of neurological, physiological and psychotic dysfunctions associated with a mental disorder such as schizophrenia, or a predisposition therefor. The invention further relates to genes and proteins, which, when varied in their normal expression, their nucleic acid sequence or in their activity, are associated with the mental disorder. Accordingly, the present invention relates to methods for diagnosis and to methods for prevention and/or treatment of a mental disorder. The present invention additionally relates to compositions for use in diagnosis and to kits for diagnosis of a mental disorder. The invention also relates to the use of a protein or polynucleotide for the manufacture of a medicament for use in the treatment and/or prevention and to a pharmaceutical composition for use in prevention and/or treatment of a mental disorder. Further, the invention relates to methods for screening for a modulator of a mental disorder.