BDKRB2 and obesity due to melanocortin 4 receptor deficiency: Therefore, considering these findings and the fact that the role of B2 receptor in SM has been poorly investigated, the aim of this study was to evaluate the B2R function in skeletal muscle fiber distribution and mitochondrial biogenesis in mice and how this receptor can contribute to an improvement of metabolic responses, diet-induced obesity (DIO) and physical performance.