Conversely, serum AAT levels were significantly lower in the T2DM+obesity group (2.539 ± 0.516 g/dL) than in the obesity (2.753 ± 0.454 g/dL) and control (3.086 ± 0.596 g/dL) groups (P<0.05). The gene discussed is SERPINA1; the disease is obesity due to melanocortin 4 receptor deficiency.