HIF1A and obesity due to melanocortin 4 receptor deficiency: These findings on the role of HIF1β and HIF1α, together with our present findings of reduced VEGF-A levels, endothelial cell numbers, and vascularity of WAT and BAT in obese adipocyte-specific HIF2α-deficient mice, unequivocally underline the primacy of adipocyte HIF2α as the major HIF isoform orchestrating the angiogenic response in the WAT and BAT in obesity.