SOX10 expression during human organ of Corti (OC) development. (A-C) Basal turn of a cochlea immunostained for SOX10 (green) at (A) W10.4, (B) W12 and (C) W19. Cell nuclei were visualized with DAPI (blue). Bracket, the prosensory domain/OC; arrowhead, inner hair cell. Abbreviations: KO, Kölliker’s organ. Scale bars = 20 μm.