Perivascular adipose tissue (PVAT) surrounding blood vessels has properties of both white and brown adipose cells and regulates cardiovascular health.[2] A study by Koenen et al. showed that deletion of the Prdm16 gene in fat cells suppresses the brown properties of PVAT, leading to vascular remodeling, vasoconstriction, and hypertension in non-obese mice.[2][3][5] These mice show increased vascular sensitivity to the vasoconstrictor angiotensin II and activation of the enzyme QSOX1, which causes vascular stiffness and fibrosis.[3][5] Blocking QSOX1 in Prdm16 null mice normalized vascular function and reduced blood pressure.[3][5] In clinical data from three biobanks, PRDM16 variants in humans are associated with higher blood pressure.[5] Activating brown fat could reduce the risk of cardiovascular disease.[2][5]