Inhibits primary neurogenesis. May be required to divert neurons along a specific differentiation pathway. Plays a role in the formation of somite boundaries during segmentation of the paraxial mesoderm (By similarity). Can bind and activate Notch-1 or another Notch receptor. The DSL domain is required for binding to the Notch receptor. Ubiquitinated by MIB (MIB1 or MIB2), leading to its endocytosis and subsequent degradation. The disease is caused by variants affecting the gene represented in this entry.