SIX3 and coloboma: A number of mammalian genes encoding transcription factors (BCOR, CBP, Chx10, Cited2, c-Maf, Foxg1, Pax2, Pax6, Ptch, Six3, Ski, Vax1 and Vax2), signaling molecules (Jnk1, Jnk2 and Shh), or members of the retinoic acid pathway have been associated with coloboma [5].