a. Overview of NR2F2 expression throughout the cochlea at E18. NR2F2 is most strongly expressed in the cochlear duct. In the apical duct, strong expression is seen in the super-medial wall (S-MW), greater epithelial ridge (GER), and lesser epithelial ridge (LER). This expression is reduced to the lesser epithelial ridge in the basal duct (arrowhead). b–e. Apical cochlear duct; f–i. Middle cochlear duct; and j–m. Basal cochlear duct. b, f & j, cell nuclei stained with DAPI; c, g & k, NR2F2 labelling; d, h & l, filamentous actin labelled by Phalloidin; and e, i & m, Merge of DAPI (blue), NR2F2 (green) and Phalloidin (red), scale bars: 100 µm in a and 20 µm in e, i & m.