HIF1A and obesity due to melanocortin 4 receptor deficiency: Excessive accumulation of visceral WAT in obesity causes adipocyte hypertrophy and hypoxia [6], leading to the induction of the key hypoxia transcription factor, hypoxia-inducible factor-1α (HIF-1α) and substantial secretion of pro-inflammatory chemokines, including monocyte chemotactic protein-1 (MCP-1) [7] and tumor necrosis factor-α (TNF-α) [8].