Cell surface receptor for PLXNB1 and PLXNB2 that plays an important role in cell-cell signaling (By similarity). Regulates GABAergic synapse development (PubMed:23699507, PubMed:29981480). Promotes the development of inhibitory synapses in a PLXNB1-dependent manner (PubMed:23699507, PubMed:29981480). Modulates the complexity and arborization of developing neurites in hippocampal neurons by activating PLXNB1 and interaction with PLXNB1 mediates activation of RHOA (By similarity). Promotes the migration of cerebellar granule cells (PubMed:17554007). Plays a role in the immune system; induces B-cells to aggregate and improves their viability (in vitro) (By similarity). Induces endothelial cell migration through the activation of PTK2B/PYK2, SRC, and the phosphatidylinositol 3-kinase-AKT pathway (By similarity). Homodimer (By similarity). Interacts with PLXNB1 (By similarity). Interacts with PLXNB2 (PubMed:17554007). Strongly expressed in lymphoid tissues, especially in the thymus, as well as in the nervous tissues (PubMed:8969198). Expressed in neurons and glia in the developing hippocampus (PubMed:29981480). Belongs to the semaphorin family.