IRS1 and type 2 diabetes mellitus: Sites annotated to 10 candidate genes for type 2 diabetes, including DUSP9, BCL11A, HNF4A, and CDKN2B, and 7 candidate genes for related metabolic traits (for example, ATP11A, ADCY5 and IRS1) had differential DNA methylation in human pancreatic islets based on sex (Additional files 11 and 12).