SIRT6 and obesity due to melanocortin 4 receptor deficiency: SIRT6 expression in the abdominal adipose tissue of patients with obesity and pre-DM is lower than that in healthy patients, while nuclear transcription factor-κB (NF-κB), peroxisome proliferator-activated receptor γ (PPARγ), and sterol regulatory element-binding protein 1 (SREBP-1) expression levels increase, suggesting their involvement in the inflammatory pathway (137).