Figure 3C. Copyright: Reprinted with permission from Elsevier from [doi:10.1016/S0925-4773(99)00017-9] Mech Dev 83: 155-9, Lopez-Rios J; Gallardo ME; Rodriguez de C rdoba S; Bovolenta P, Six9 (Optx2), a new member of the six gene family of transcription factors, is expressed at early stages of vertebrate ocular and pituitary development. Copyright 1999.