To access the data, click or select the words “Appendix 1.” A: In WT embryos, the keratin 12 protein was negative in the cornea at E13.5. B: In WT embryos, the keratin 12 immunoreactivity is observed in the corneal epithelium at E15.5. C: Keratin 14 was observed in the basal cells of the WT corneal epithelium at E17.5. D: Keratin 14 was markedly expressed in mutant epithelial nodules at E17.5. E: Focal hyperproliferation of the conjunctival epithelium was also observed in the mutant embryos at E17.5. F and G: At E13.5, the incidence of BrdU-labeling in the embryonic corneal epithelium was similar between the WT and mutant embryos. H and I: At E13.5, the corneal stroma of the WT and mutant littermates was not labeled with anti-keratocan antibodies.J: At E15.5, the corneal stroma of the WT was labeled with collagen type I. Scale bar represents 10 μm (A-J).