INS and obesity due to melanocortin 4 receptor deficiency: The mammalian target of rapamycin complex 1 (mTORC1) and its downstream target protein, ribosomal S6 kinase 1 (S6K1), regulate insulin-induced protein synthesis and have emerged as critical signaling components in obesity-induced IR due to homologous desensitization of the PI3K/Akt pathway [6].