IRS1 and obesity due to melanocortin 4 receptor deficiency: Some of the genes present in these modules have been functionally associated with obesity, including Irs1 (105), Sdccag8 (106, 107), Negr1 (108–111), Ksr2 (112, 113), Tlr4 (114, 115), and Sh2b1 (116, 117).