AKT1 and obesity due to melanocortin 4 receptor deficiency: It’s anti-obesity mechanism involves the down-regulation of the major transcription factors of the adipogensis pathway including PPAR-γ and C/EBP-α by regulation of Akt and ERK1/2 pathway, and resultant down-regulation of lipid metabolizing enzymes, FAS, LPL and aP2 which are involved in the transport, uptake and synthesis of lipids needed for the accumulation of lipid in adipocytes.