INS and obesity due to melanocortin 4 receptor deficiency: Defects in Akt phosphorylation, as seen in impaired insulin activation, are associated with development of muscle and adipose insulin resistance in obesity and T2DM (Naowaboot et al., 2012; Joshi et al., 2013; Luna-Vital & De Mejia, 2018; Kim et al., 1999).