Ligand for multiple Notch receptors and involved in the mediation of Notch signaling. May be involved in cell-fate decisions during hematopoiesis. Seems to be involved in early and late stages of mammalian cardiovascular development. Inhibits myoblast differentiation (By similarity). May regulate fibroblast growth factor-induced angiogenesis. Interacts with NOTCH1, NOTCH2 and NOTCH3. Widely expressed in many tissues, with highest expression in brain, heart, muscle and thymus. At 8.75-9.75 dpc expression was detected in structures that include those destined to contribute to the cardiovascular system of the adult heart. Expression was also detected in the mesencephalon and rhombencephalon. The DSL domain is indispensable and sufficient for binding to NOTCH2.