IGF2 and schizophrenia: Therefore, this study aims to explore the potential function of IGF-2 signaling in the pathophysiology of schizophrenia by examining (1) whether serum IGF-2 was altered in Han Chinese patients who suffered from schizophrenia and (2) whether changes in IGF-2 levels were associated with the psychopathological symptoms as well as cognitive deficits of the patients.