Functions in cell-cell adhesion, cell migration and axon guidance, exerting an attractive or repulsive role depending on its interaction partners (By similarity). Modulates cadherin-dependent cell-cell adhesion and cell sorting (PubMed:20027292, PubMed:19492039). Plays a role in the spatial organization of brain neurons. Plays a role in vascular development. Plays a role in cell-cell adhesion via its interaction with latrophilins that are expressed at the surface of adjacent cells. Mediates axon attraction towards cells expressing ntn1. Mediates axon growth cone collapse and plays a repulsive role in neuron guidance via its interaction with unc-5 family members. Plays a role in the regulation of the density of glutamaergic synapses (By similarity). Plays a role in signaling cascades downstream of fgfr1, and possibly also other fgfr family members (PubMed:14688794). Plays a role in embryonic morphogenesis, but not in embryonic patterning (PubMed:19492039). Interacts with fgfr1 and fgfr4 (PubMed:14688794). Interacts with rnd1, cdh1 and pcdh8 (PubMed:20027292). Interacts (via extracellular domain) with unc5b and unc5d (via extracellular domain) (PubMed:19492039). Detected on dendritic punctae that colocalize in part with glutamaergic synapses, but not with GABAergic synapses. Proteolytic cleavage in the juxtamembrane region gives rise to a shedded ectodomain. First detected at the mid-blastula transition. In gastrula, detected at the marginal zone. In neurula, detected at the boundary between midbrain and hindbrain, and at the anterior neural ridge. In tadpoles, detected in telencephalon, diencephalon, at the boundary between midbrain and hindbrain, in ears and branchial arches. N-glycosylated. Proteolytic cleavage in the juxtamembrane region gives rise to a soluble ectodomain. Cleavage is probably effected by a metalloprotease.