As demonstrated in Figure 2D, in MCT-PAH rats, linear regression analysis demonstrated that lung PRDC band intensity negatively correlated with the severity of MCT-PAH as measured by RVSP, PASP, mPAP, and RVHI, which naturally presented a necessary supplement for the deficiency of human data presented in Figure 1. This evidence concerns the gene GREM2 and pulmonary arterial hypertension.