It has been reported that CCL5 could be produced by endothelial cells in patients with PAH [28], where CCL5 deficiency increased apoptosis and tube formation of pulmonary artery endothelial cells (PAECs), and suppressed proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) [30]. Here, CCL5 is linked to pulmonary arterial hypertension.