The cardiovascular system has the life-providing task of delivering oxygen and any flaw in this system can be life-threatening. This has encouraged extensive studies to elucidate the mechanisms behind cardiovascular development/homeostasis. The zebrafish has emerged as a formidable tool to speed up this quest, as illustrated in a recent issue of Nature Genetics.((1)) Baculovirus IAP repeat c2 (BIRC2), also termed cellular inhibitor of apoptosis (cIAP)-1, was found to specifically prevent endothelial cells (ECs, lining the inside of vessels) from going into suicide mode ('apoptosis') and so preserve vessel integrity. Here, we summarize the factors determining vascular integrity and elaborate on the suitability of the zebrafish to study this phenomenon.