Foxd1 is transcription factor required for formation of positional identity in the developing retina, regionalization of the optic chiasm and morphogenesis of the kidney. Mice lacking Foxd1 show disrupted cell identity in the ventrotemporal area of the retina and aberrant morphogenesis of the optic chiasm. Their kidneys remain fused, have a disorganised ureteric tree and fail to ascend to a lumbar position.