ANGPT1 and cancer: The prevailing concept holds that the tumor vasculature is formed via a mechanism of tumor angiogenesis: pre-existing blood vessels, which are stimulated by various angiogenic growth factors secreted by cancer cells, such as vascular endothelial growth factor (VEGF), angiopoietin (Ang)-1, and Ang-2, sprout into cancer cell clusters to form tumor vasculature [1], [2].