SMAD6 and pulmonary arterial hypertension: We demonstrated that expression of CCDC80, SMAD6, AGR2, and GZMA was significantly dysregulated in two cohorts of human PAH patients (Mura et al., 2012; Zhao Y. et al., 2014; Zhao Y.D. et al., 2014) and in three rodent PAH models caused by: (i) treatment with a VEGF receptor inhibitor under conditions of hypoxia (Moreno-Vinasco et al., 2008); (ii) overexpression of Fra-2, a causative gene for systemic sclerosis (Biasin et al., 2014); and (iii) schistosomiasis (Graham et al., 2013).