FLT1 and Pulmonary arterial hypertension associated with portal hypertension: Semi-quantitative immunohistochemistry measurements agreed with these qualitative observations, with PoPH peri-central regions demonstrating higher ESR1 and FLT1 protein staining, and lower BMPR2 protein staining, relative to non-PoPH cirrhosis, but no difference in staining of any protein across the peri-portal region (Supplementary Figure 7, Supplementary Table 3).