TIMP2 and obesity due to melanocortin 4 receptor deficiency: These results could indicate that decreased TIMP2 expression in PBMC could be a marker of improvement of obesity, corroborating with Yasmeen et al. (26), in which the alteration or increase in serum levels of TIMP2 resulted in the accumulation of extracellular matrix cells, tissue fibrosis and an imbalance of metalloproteinases in the obesity condition.