In fact, our group has previously demonstrated the presence of cells expressing CD45 and CD133 markers in the wall of pulmonary arteries in COPD patients [6], potentially suggesting recruitment of bone marrow-derived progenitor cells that might eventually contribute to an ongoing process of endothelium repair or be involved in the pathogenesis of vessel remodelling [6]. Here, PROM1 is linked to chronic obstructive pulmonary disease.