Although the FSTL1 protein has been described as an adipomyokine and although it has recently received a substantial amount of attention, only a limited number of studies have provided a possible link to obesity, namely by pointing out its role in inflammation and adipocyte cell fate determination and describing its methylation status in obese individuals [5, 15, 16]. This evidence concerns the gene FSTL1 and obesity due to melanocortin 4 receptor deficiency.