SGK1 and obesity due to melanocortin 4 receptor deficiency: The role of SGK1 in the development of obesity is emphasized by the finding that the I6C/E8CC/CT SGK1 variant is related to increased body weight (Busjahn et al., 2004) and is more prevalent in patients with type 2 diabetes than in individuals without a family history of diabetes (Schwab et al., 2008).