For appropriate membrane repair, a series of steps must occur including an influx of calcium, activation of vesicular exocytosis, and upregulation of annexin production.54 Annexins act as environmental sensors that signal cell adaptation to stress, that are highly abundant in endothelial cells and have been implicated in in human airway epithelial cell membrane repair mechanisms.35, 55, 56, 57 This study demonstrated an increase in anxa5 gene production in BPD animals treated with MSCs. The gene discussed is ANXA5; the disease is bronchopulmonary dysplasia.