CTNND1, which encodes for delta-catenin and is an important negative regulator within the canonical Wnt signaling pathway, was downregulated in PAECs from PAH subjects; downregulation of beta-catenin and canonical Wnt signaling has previously been linked to endothelial proliferation in PAH23, observed in a monocrotaline model of PH24, and tied to carcinogenesis25. This evidence concerns the gene CTNNB1 and pulmonary arterial hypertension.