This study indicated that serum IGF-2, IGFBP-3 and IGFBP-7 levels of Han Chinese schizophrenia patients were decreased and serum IGF-2 levels were associated with both negative and cognitive symptoms of the patients, indicating that altered IGF-2 signaling probably contributes to the psychopathology and cognitive impairments of schizophrenia. The gene discussed is IGFBP3; the disease is Cognitive impairment.