Research published in the journal Nature has suggested that transplantation of rod precursor cells into an animal model with no functioning rods may be capable of restoring some useful vision. The study, conducted by researchers at University College London’s Institute of Ophthalmology, demonstrated that visual signaling to higher visual areas of the brain was detectable following cell transplantation. The results indicate that transplantation of sufficient numbers of cells may be a key requirement in restoring functional vision and that such numbers may be achieved by harvesting cells at the right developmental stage using the rod-specific transcription factor, neural retina leucine zipper or “Nrl”.