Receptor involved in axon guidance during development (PubMed:15105459). Acts as a multifunctional regulator of pathfinding that simultaneously mediates NELL2 repulsion, inhibits SLIT repulsion, and facilitates Netrin-1/NTN1 attraction. In spinal cord development plays a role in guiding commissural axons probably by preventing premature sensitivity to Slit proteins thus inhibiting Slit signaling through ROBO1/ROBO2. Binding OF NELL2 to the receptor ROBO3 promotes oligomerization of ROBO3, resulting in the repulsion of commissural axons in the midline. ROBO3 also indirectly boosts axon attraction to NTN1 without interacting with NTN1 itself (By similarity). . This is the function of ENSG00000154134 (ROBO3, roundabout guidance receptor 3).