(A) Analysis based on 47 candidate NCC genes indicates that 43 genes were expressed and 4 were not expressed in the periocular region. Of the 43 expressed genes, 20 were downregulated, 10 were constitutively expressed, and 7 were upregulated during corneal development. (B-D) Section in situ hybridization of E3, E5, and E7 anterior eyes indicating that: (B) MSX2 is strongly expressed in the periocular region but undetectable in the corneal endothelium and stroma; (C) SNAI2 is maintained at all three time points; and (D) RHOB is minimal in the periocular region, but it is strongly expressed in the corneal endothelium and stroma. Arrow indicates periocular region and arrowheads indicate corneal endothelium. Abbreviations: pNC, periocular neural crest; ec, ectoderm; oc, optic cup; L, lens; ep, epithelium; en, endothelium; st, stroma. Scale bars: 100 μm.