Mediates selective neuronal growth and axon targeting. Contributes to the guidance of developing axons and remodeling of mature circuits in the limbic system. Essential for normal growth of the hippocampal mossy fiber projection (By similarity). Expressed on limbic neurons and fiber tracts as well as in single layers of the superior colliculus, spinal cord and cerebellum. Belongs to the immunoglobulin superfamily. IgLON family.