The Notch receptors are a type I transmembrane protein family that share structural characteristics including an extracellular domain consisting of multiple epidermal growth factor-like (EGF) repeats, and an intracellular domain consisting of multiple, different domain types. They are highly conserved from invertebrates to mammals.Notch 1 and Notch 2 exhibit the highest structural similarity among the four mammalian Notch receptors (Notch 1-4). Notch 1 and Notch 2 are reported to be functionally redundant. Notch 2 is expressed by Pre-B cells, double negative, and CD8 single positive thymocytes, brain, and lung cells. Notch 2 functions as a receptor for Jagged and Delta ligands and may play a role in vascular, renal and hepatic development.