In mouse models relevant to obesity and type 2 diabetes, such as ob/ob and C57BL/6 J DIO mice on high fat diet (HFD), treatment with CNX-013-B2 resulted in significant improvement in insulin sensitivity, control of fed and fasting glucose, fed and fasting triglyceride and cholesterol, a reduction in adiposity and body weight gain. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.