The heart is the first organ to form during development in vertebrates, and many organs start to develop adjacent
to the cardiovascular system. Endothelial cells (ECs) form the inner cell lining of blood vessels and represent the major
cell type that interacts with developing organs including the pancreas. ECs receive signals from the developing pancreas
to grow and, at the same time, release signals to determine cell-fate specification, morphogenesis and function of the
pancreas. In addition to promoting survival of pancreatic islets, in this review, we discuss the role of the vascular niche
and angiogenic factors, particularly VEGFA, during pancreatic beta cell development, regeneration and pathophysiological
progression of diabetes. Nevertheless, unraveling the molecular signals involved in pancreatic beta cell development and
regeneration may shed light into novel drug development to treat diabetes.