Although impaired muscle anabolism in the latter studies could not be explained by impaired signaling through S6K1, muscle from mice with obesity were characterized by low formation of the active translation initiation eukaryotic initiation factor 4F (eIF4F; Drake et al., 2010), which signals upregulation of protein synthesis in muscle (Pain, 1996). This evidence concerns the gene RPS6KB1 and obesity due to melanocortin 4 receptor deficiency.