miR-4640-5p was upregulated in lung tissues collected from COPD-PH compared to a normal lung [45] and high levels of miR-4640-5p were able, in pulmonary vascular smooth muscle cells, to induce a decrease in NOS1 expression and an increase in cell proliferation [45], thus causing thickening of the vessel wall and progression of the disease [45]. Here, NOS1 is linked to chronic obstructive pulmonary disease.