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 (PubMed:10433822, PubMed:24560577). Interaction with the intracellular domain of FLRT3 mediates axon attraction towards cells expressing NTN1 (PubMed:24560577). 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 (PubMed:11734623). Homodimer. Dimerization is mediated by the extracellular domain and is independent of SLIT liganding (By similarity). Interacts with SLIT1 (PubMed:10433822) Interacts with SLIT2 (By similarity). Interacts with FLRT3 (PubMed:24560577). Interacts with MYO9B (via Rho-GAP domain) (By similarity). Detected at growth cones in thalamus neurons (PubMed:24560577). PRRG4 prevents cell surface location and both colocalize in the Endoplasmic reticulum/Golgi adjacent to the cell nucleus (By similarity). Detected in embryonic thalamus neurons (at protein level) (PubMed:24560577). Expressed in embryonal spinal chord. Expressed in embryonal lung, and in adult lung bronchial epithelial cells of large proximal airways. Earliest and highest expression at 11 dpc. Expression is detected in developing somits, brain, neural tube, and pericardiac mesenchyme. By in situ hybridization is detected in marginal zones bordering the mitotically active periventricular region, weakly extending to the ventral aspect impinging on motor neuron columns. Also detected in the ventral third of the developing neural tube, and in spinal cord throughout the full length of the neural tube. Also detected at 17.5 dpc in lung mesenchyme. Expressed at 11.5 dpc in spinal cord, predominantly localized to postcrossing commissural axons. Ubiquitinated. May be deubiquitinated by USP33. Mice show defects in commissural axon guidance in spinal cord including midline recrossing and an altered lateral and ventral funiculi projection. The phenotype resembles that of a SLIT1;SLIT2;SLIT3 triple mutant. They also mimick a naturally occurring human homozygous deletion mutant detected in a small lung cancer cell line, frequently die at birth by respiratory failure with accompanying abnormal lung histology. Surviving mice develop bronchial hyperplasia. Belongs to the immunoglobulin superfamily. ROBO family.