The role of AP-2α in eye development has been established in several studies, perhaps the most compelling of which is the demonstration that Tfap2a knockout mouse embryos exhibit grossly abnormal ocular development in the form of anophthalmia, aphakia, absent cornea, coloboma, lens stalk, lack of ciliary body and iris formation, absent eyelids, and ectopic neural retina that replaces part of the retinal pigmented epithelium [22,23]. The gene discussed is TFAP2A; the disease is coloboma.