May be involved in the specification and maintenance of differentiation of distinct neuronal and neuroendocrine tissues. Early marker for the pituitary and pineal lineages, it may be involved in specifying these lineages. Interacts with ldb1 and with the N-terminus of rnf12. In dorsal regions at neural tube and tailbud stages and in adults predominantly in the pituitary gland and weakly in the eye and brain. First detectable at the neural plate stage in the stomodeal-hypophyseal (pituitary) anlage and in the neural plate. At later stages it persists in the pituitary and pineal, retina, hindbrain and spinal cord.