May have a regulatory function possibly in association with the Notch gene product. During early neurogenesis, expression is ubiquitous. During later stages, expression concentrates at the central nervous system. The protein has many AA homomeric domains: 21 poly-Gln runs (from 5 to 16 AA in length), 4 poly-Gly (6 to 10 AA), 3 poly-Asn (3 X 5 AA), 1 poly-Ala (10 AA) and 1 poly-Thr (5 AA) runs. Belongs to the mastermind family.