TET1 and obesity due to melanocortin 4 receptor deficiency: Furthermore, in 2007, the FTO (fat mass and obesity associated) gene was found to encode a functional homologue of AlkB (Gerken et al, 2007; Sanchez-Pulido and Andrade-Navarro, 2007), and two more genes, TET1 and TET2 (Tahiliani et al, 2009; Ito et al, 2010), suggested possibility as a similar mechanism.