HIF1A and obesity due to melanocortin 4 receptor deficiency: HIF-1α can be activated by hypoxia in obesity-related adipose tissue, and HIF-1α promotes the expression of collagen remodeling genes such Collagen type I alpha 1 chain (COL1A1) and Lysyl oxidase (LOX) in ovarian surface epithelial cells and activates Macrophage Type 2 (M2) macrophages (69–72).