Salero, E. et al. Cell Stem Cell 10, 88–95 (2012).

The stem cell community continues its search for cells with stem cell properties that can be extracted from adult humans, preferably from a relatively accessible tissue source. Collecting these cells might offer some promise for cell-replacement therapies and can help researchers understand the biology of diseases as well as fate choice and differentiation processes. Salero et al. looked inside the human eye and found a subpopulation of adult retinal pigment epithelial cells that can be expanded in culture and differentiated into both neural and mesenchymal progeny. It is unclear whether these cells have stem cell properties in vivo, but their in vitro properties make them an interesting candidate for obtaining sources of proliferative and lineage-differentiated human cells.