CCL2 and obesity due to melanocortin 4 receptor deficiency: The obesity-related chronic low-grade inflammation, characterized by raised levels of pro-inflammatory molecules (such as leptin, resistin, chemokine (C-C motif) ligand 2 (CCL2), interleukin (IL)-6, IL-1β, IL-8, tumor necrosis factor (TNF)-α) and decreased levels of adiponectin, may have negative effects on the lung parenchyma and bronchi [72].