Specifically, the interaction between ligand JAG1 and NOTCH2 receptor requires several functional motifs, such as the C2-like domain, delta-Serate-lag2 (DSL) domain, epidermal growth factor-like (EGF-like) repeats of JAG1, and extracellular EGF-like repeats on NOTCH2 (Chillakuri et al., 2013; Kopan and Ilagan, 2009; Lindsell et al., 1995), and the mutation of this pathway identified in children with Alagille syndrome. This evidence concerns the gene JAG1 and Alagille syndrome.