S100A4 and obesity due to melanocortin 4 receptor deficiency: In addition, new blood vessel formation (angiogenesis), including VSMC, is required for a correct adipose tissue expandability.25 Moreover, inflammation and vascular dysfunction contribute to the development of obesity and insulin resistance.26 Therefore, it is tempting to speculate that S100A4 secretion by immune cells infiltrated in adipose tissue during obesity acts on VSMC and thereby regulates the vascular tone, distribution of blood flow, as well as angiogenesis, inflammatory processes, and redox status.