OTX2 is a member of a highly conserved family of bicoid-like homeodomain transcription factors responsible for the regulation of cerebellar development. Orthodenticle homeobox 2 (OTX2) controls essential, homeostatic retinal pigment epithelial (RPE) genes in the adult. Mutations in OTX2 are mostly identified in patients with anophthalmia/microphthalmia with variable severity. The OTX2 homeobox gene plays a crucial role in craniofacial morphogenesis during early embryo development. Otx2 knockout embryos fail to form a head. The Otx2 homeodomain transcription factor is essential for gastrulation and early neural development.