FNDC5 and obesity due to melanocortin 4 receptor deficiency: These genes all code for proteins that are involved in fat metabolism, which include ADIPOR1 (coding for adiponectin receptor 1, which takes part in signaling pathways involved in regulation of fatty acid oxidation), FTO (coding for fat mass and obesity-associated protein, which is implicated in obesity) and FNDC5 (coding for a hormone for white fat conversion to brown fat) [102].