TCF7L2 and obesity due to melanocortin 4 receptor deficiency: The direct association of TCF7L2 with obesity is unclear; however, it is well-established that TCF7L2 is expressed in adipose tissue (Cauchi et al., 2006, 2008; Kovacs et al., 2008) and involved in Wnt/β-catenin signaling dependent regulation of adipogenesis (Ross et al., 2000, 2002; Cawthorn et al., 2007).