May be involved in eye development. Interacts with TLE4 and TLE5. In the developing embryo, expressed mainly in the ventral optic stalk, optic chiasma, the neural retina and the primordial tissues that give rise to the pituitary/hypothalamus axis. Not expressed in the lens placode. Expression is first detected in the embryo at 8 dpc. Belongs to the SIX/Sine oculis homeobox family.