UCP2 and obesity due to melanocortin 4 receptor deficiency: UCP2 expression variants were found to be associated with insulin sensitivity and diabetes mellitus (Jia et al., 2009; Diano and Horvath, 2012; Sreedhar and Zhao, 2017), obesity and metabolic syndrome (Li et al., 2003; Ricquier, 2007; Jia et al., 2009; Dinh et al., 2015; Sreedhar and Zhao, 2017), cardiac diseases (Brand and Esteves, 2005), immunity process (Emre et al., 2007; Emre and Nubel, 2010), tumorigenesis and cancer (Selimovic et al., 2008), aging (Brand and Esteves, 2005), and neurological diseases (Toda and Diano, 2014).