APOB and schizophrenia: Therefore, the main purposes of this study were (1) to identify the association between ApoE polymorphism rs429358 and schizophrenia; (2) to analyze the relationship between ApoA1 or ApoB levels and clinical symptoms in patients with schizophrenia; and (3) to explore whether the relationship between serum levels of ApoA1 or ApoB and clinical symptoms was regulated by ApoE polymorphism rs429358.