Recently, Säleby et al. reported that VEGF-D levels were elevated in patients with PAH, CTEPH, PH-HFpEF, and PH-HFrEF compared to control subjects and HF patients without PH, with its levels in PH-HFrEF patients being significantly higher compared to all other etiologies of PH (72). The gene discussed is VEGFD; the disease is hydrops fetalis.