FOXP2 and schizophrenia: Therefore, to the best of our knowledge, this study is the first to investigate: (1) whether the FOXP2 polymorphism rs10447760 affects cognition differently as a function of sex; (2) whether BMI was associated with cognitive deficits in schizophrenia patients; (3) and whether any relationship between BMI and cognitive deficits in schizophrenia was further altered by sex.