Although our previous study has shown that FOXP2 polymorphisms (rs10447760) is associated with cognitive deficits in chronic schizophrenia (Lang et al., 2019), it remains unclear whether there are sex differences in the degree of contribution of genetic factors to cognitive deficits in schizophrenia; whether there are sex differences in the influences of BMI on cognitive deficits in schizophrenia; and/or whether there are sex differences in the effects of genetic contributions and BMI on cognitive deficits in schizophrenia. This evidence concerns the gene FOXP2 and schizophrenia.