Closely following reprogramming of bone marrow cells into retinal cells, researchers have now demonstrated that induced pluripotent stem cells (iPS cells) can turn out retinal cells as well: the scientists have "grown multiple types of retina cells from two types of stem cells - suggesting a future in which damaged retinas could be repaired by cells grown from the patient's own skin. Even sooner, the discovery will lead to laboratory models for studying genetically linked eye conditions, screening new drugs to treat those conditions and understanding the development of the human eye. ... This is an important step forward for us, as it not only confirms that multiple retinal cells can be derived from human iPS cells [but] also shows how similar the process is to normal human retinal development. That is quite remarkable given that the starting cell is so different from a retinal cell and the whole process takes place in a plastic dish. We continue to be amazed at how deep we can probe into these early events and find that they mimic those found in developing retinas. Perhaps this is the way to close the gap between what we know about building a retina in mice, frogs and flies with that of humans."