May be essential for the survival of the neurosensory epithelium of the inner ear. Ear specific. Expressed in the cochlea and vestibule, but not in the cochlear nerve, cochlear nucleus, spinal chord, muscle, cerebral cortex, cerebellum, diencephalon and olfactory bulb. In the cochlea, expressed in fibrocytes of the spiral limbus, spiral ligament and suprastrial zone. In the vestibule, expressed in cells located to the stroma below the macular and crista sensory epithelia and in the subepithelial layer of the walls of semicircular canals and maculae. Belongs to the otospiralin family.