ESR1 and Pulmonary arterial hypertension associated with portal hypertension: PoPH samples demonstrated relatively more intense staining for both the ESR1 and FLT1 proteins (Fig. 1D, Supplementary Fig. 6), and relatively less staining for the BMPR2 protein (Fig. 1E), in the region surrounding liver central veins (the “peri-central” zone) relative to non-PoPH cirrhosis tissue.