Downstream effector of Notch signaling. Involved in the regulation of liver cancer cells self-renewal (PubMed:25985737). Involved in angiogenesis acting downstream of Notch at branch points to regulate vascular density. Proposed to integrate endothelial Notch and Wnt signaling to control stalk cell proliferation and to stablilize new endothelial connections during angiogenesis (PubMed:19154719). During somitogenesis involved in maintenance of proper somite segmentation and proper numbers of somites and vertebrae. Required for proper anterior-posterior somite patterning. Proposed to function in a negative feedback loop to destabilize Notch 1 intracellular domain (NICD) and down-regulate the Notch signal, preventing expansion of the Notch signal into the anterior somite domain (By similarity). Interacts with LEF1. In endothelial cells by Notch signaling. Belongs to the NRARP family.