ESR1 and pulmonary arterial hypertension: The ERα antagonist, 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy) phenol]-1H-pyrazole dihydrochloride, but not the ERβ antagonist, 4-[2-phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl]phenol, inhibited 16αOHE1-induced ROS formation in control and PAH-hPASMCs (Figure S2).