Based on a study with mouse proteins, NOTCH3 receptor binds to DLL1 ligand (Shimizu et al. 2000). The interaction of DLL1 and NOTCH3 is implicated in functional differentiation of activated CD4+ T lymphocytes into type 1 helper T cells (Th1) (Maekawa et al. 2003). The effect of Fringe-mediated modification of NOTCH3 on its interaction with DLL1 is poorly studied (Hou et al. 2012).