To determine whether MBH-specific overexpression of human SH2B1 protects against obesity, AAV9-CAG-SH2B1 or AAV9-CAG-GFP (control) vectors were bilaterally injected into the MBH of C57BL/6J males. The gene discussed is SH2B1; the disease is obesity due to melanocortin 4 receptor deficiency.