GRHL2 and deafness: However, a recent examination of deafness genes in the non-human primate model marmoset (Callithrix jacchus) has revealed that GRHL2 expression is prevalent in cochlear duct lining cells, hair cells, and supporting cells of the inner ear (Hosoya et al., 2016), denoting that the definitive role of GRHL2 in the inner ear development needs further investigations.