Neurogenic locus notch homolog protein 2 (Notch 2) functions as a receptor for membrane-bound ligands Jagged1, Jagged2 and Delta1 to regulate cell-fate determination. Upon ligand activation through the released notch intracellular domain (NICD), Notch 2 forms a transcriptional activator complex with RBP-J kappa and activates genes of the enhancer of split locus. Notch 2 affects the implementation of differentiation, proliferation and apoptotic programs. Defects in Notch 2 are the cause of Alagille syndrome type 2 (ALGS2). Alagille syndrome is an autosomal dominant multisystem disorder defined clinically by hepatic bile duct paucity and cholestasis in association with cardiac, skeletal, and ophthalmologic manifestations. There are characteristic facial features and less frequent clinical involvement of the renal and vascular systems.