The behavior of the cells that make up our blood vessels is crucial to our well-being. Conditions such as inflammation, oxygen deprivation and viral infection can stress these cells and disrupt the formation of new, often pathological, blood vessels. Now a team of researchers led by Jean-Philippe Gratton, chair of the Department of Pharmacology and Physiology at Université de Montréal and a specialist in vascular biology, has discovered a previously unknown pathway leading to the formation of new blood vessels, a process known as angiogenesis.