Receptor for SLIT1 and SLIT2 that mediates cellular responses to molecular guidance cues in cellular migration, including axonal navigation at the ventral midline of the neural tube and projection of axons to different regions during neuronal development. Interaction with the intracellular domain of FLRT3 mediates axon attraction towards cells expressing NTN1 (By similarity). In axon growth cones, the silencing of the attractive effect of NTN1 by SLIT2 may require the formation of a ROBO1-DCC complex (By similarity). Plays a role in the regulation of cell migration via its interaction with MYO9B; inhibits MYO9B-mediated stimulation of RHOA GTPase activity, and thereby leads to increased levels of active, GTP-bound RHOA (By similarity). May be required for lung development (By similarity). Homodimer. Dimerization is mediated by the extracellular domain and is independent of SLIT liganding (By similarity). Interacts with SLIT1 (By similarity). Interacts with SLIT2. Interacts with FLRT3. Interacts with MYO9B (via Rho-GAP domain) (By similarity). Detected at growth cones in thalamus neurons (By similarity). PRRG4 prevents cell surface location and both colocalize in the Endoplasmic reticulum/Golgi adjacent to the cell nucleus (PubMed:28859078). Expressed in embryonal brain and spinal chord. In the developing spinal cord expressed at E11 and E13 dorsally in the region of the commissural and association neuron cell bodies and ventrally in subpopulations in the motor column. In the brain detected between E15 and E18, between P0 and P10, and in adult in regions of the hippocampal system and the basal ganglia. Detected at E18, between P0 and P10, and in adult in anterior olfactory nuclei, regions of the cortex and basal telencephalon. Ubiquitinated. May be deubiquitinated by USP33. Belongs to the immunoglobulin superfamily. ROBO family.