EDNRB and cardiovascular disorder: ECETB receptors mediate production of vasodilator, antiproliferative, and anti-inflammatory molecules (eg, nitric oxide [NO])11,12; clearance of ET-1 from the circulation13,14; and regrowth of damaged EC.15 VSMC ETB can mediate vascular contraction, similar to the ETA subtype,16 and may compensate for ETA receptor dysfunction.17 ETB upregulation in VSMC may mediate vasoconstriction and proliferation in cardiovascular disease.18,19