Intercellular signal is essential for a variety of patterning events during development: signal produced by the notochord that induces ventral cell fate in the neural tube and somites, and the polarizing signal for patterning of the anterior-posterior axis of the developing limb bud. This protein is surely part of a signaling pathway, it has probably a repressive activity on cell proliferation. As NBCC syndrome is a chromosome instability syndrome, this protein may have a role in DNA maintenance, repair and/or replication. It seems to have a tumor suppressor function, as inactivation of this protein is probably a necessary, if not sufficient, step for tumorigenesis.