Besides the fact that it is one of the most commonly analyzed inflammatory mediators in respiratory diseases, there is consistent evidence of an association between obesity and higher IL-6 levels; and IL-6 constitutes an important proatherogenic biomarker, and it is one of the systemic inflammation biomarkers most consistently associated with a risk of cardiovascular morbidity and mortality [21,22]. This evidence concerns the gene IL6 and obesity due to melanocortin 4 receptor deficiency.