RARRES2 and obesity due to melanocortin 4 receptor deficiency: The chemerin-CMKLR1 axis regulates lipid and glucose metabolism (Kennedy and Davenport, 2018), and is associated with chronic inflammation, obesity, and obesity-related disorders such as insulin resistance and metabolic syndrome, with several compounds and antibodies under preclinical or early clinical investigation (Goralski et al., 2007; Kennedy et al., 2016; Trilleaud et al., 2021).