May play a role in anteroposterior axis elongation. Expression begins in the posterior region of the embryo and this posterior restriction persists at the 4 s stage. At early somite stages, expressed along the neural tube with lower levels in the lateral and paraxial mesoderm. Expression decreases caudally and rostrally becomes restricted to the ventral part of the brain. Widespread in the spinal cord at 30 hours post-fertilization (hpf) and is also expressed in the lens from this time. At 40 hpf, expression is restricted to the lens. Expression begins at 80% epiboly and is extinguished by 48 hours post-fertilization. Belongs to the immunoglobulin superfamily. DCC family.