However, in cases of obesity, PVAT volume increases and becomes dysfunctional, contributing to macrophage infiltration and changes in cell composition, molecular characteristics, and large-scale secretion of pro-inflammatory and anti-vasodilatory factors, such as leptin, resistin, Tumor Necrosis Factor-Alpha (TNF-α), monocyte chemoattractant peptide-1 (MCP-1), Interleukin 6 (IL-6), and Interleukin 1(IL-1) [39]. This evidence concerns the gene CCL2 and obesity due to melanocortin 4 receptor deficiency.