MMP1 and pulmonary arterial hypertension: Among these genes, THBS1 encodes thrombospondin-1 (TSP1), which has been implicated in vascular dysfunction in pulmonary hypertension and various cerebrovascular diseases (Krishna and Golledge, 2013; Rogers et al., 2017), and MMP1 (which encodes a matrix metalloprotease) has been shown to promote the occurrence of hypertension, atherosclerosis and thrombosis (Dollery and Libby, 2006; Trivedi et al., 2009; Agrinier et al., 2013).