NRG3 and Cognitive impairment: Therefore, in this study, we sought to determine (1) whether the NRG3 polymorphism rs10748842 might affect cognitive impairment in schizophrenia; (2) whether BMI might affect cognitive impairments in schizophrenia; and (3) whether NRG3 polymorphism rs10748842 mediates the effects of BMI on cognitive impairment in schizophrenia in a large sample of Chinese Han population.