Ligand for multiple Notch receptors and involved in the mediation of Notch signaling. May be involved in cell-fate decisions during hematopoiesis. Enhances fibroblast growth factor-induced angiogenesis (in vitro). Seems to be involved in early and late stages of mammalian cardiovascular development. Inhibits myoblast differentiation. May regulate fibroblast growth factor-induced angiogenesis. Interacts with NOTCH1 (PubMed:28089369). Interacts with NOTCH2 and NOTCH3 (By similarity). Widely expressed in a variety of tissues. Expression is seen in E11.5-E14.5 embryos in four distinct regions of the ventricular zone in the developing spinal cord.