May be involved in maintenance as well as cellular differentiation of retinal interneurons, such as bipolar cells. May play a role in establishing interneuronal cell classes in nonsensory as well as sensory systems. Interacts with UBE2I. Highly expressed in the central and outer tiers of the inner nuclear layer of the retina. Significant levels were first detected at the 14-somite stage (16 hours post-fertization; hpf) and increased by the prim-11 stage (28 hpf). At 16 hpf expression is observed in a small subset of neurons in the spinal cord and at 18 hpf in the developing hindbrain. At 28-32 hpf, significant levels of expression is seen in presumptive neurons along the rostral-caudal axis of the hindbrain and the spinal cord. During later stages of development expression is restricted to the developing retina and no longer detected in the hindbrain or spinal cord. The NLS interacts with UBE2I. Belongs to the paired homeobox family.