SDC4 and obesity due to melanocortin 4 receptor deficiency: Considering the multicellular composition of WAT and the involvement of several cells, such as macrophages, adipocyte progenitors, and mature adipocytes, in obesity-induced WAT fibrosis [42], as well as the ubiquitous expression pattern of SDC4 [11], we cannot, however, rule out the idea that compensatory mechanisms prevented the development of gWAT fibrosis in the obese female Sdc4-/- mice.