With so many researchers working on it, potential improvements to the process of reprogramming normal cells into stem cells are arriving rapidly. Here is one example: "Scientists believe there is much promise for induced pluripotent stem cells: normal adult cells that have been manipulated to develop the stem-cell-like ability to differentiate into other types of cells, potentially to be used to repair damaged tissue and treat the ravages of disease. But making these so-called iPS cells is both time-consuming and inefficient. Now researchers [have] discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. The finding could eliminate a major bottleneck in the generation of iPS and embryonic stem cells - that of removing molecular tags called methyl groups from specific regions of cellular DNA. Without this process of demethylation, the stem cell genes are silent in adult, or differentiated, cells. ... The mechanism of DNA demethylation in mammals has eluded us for decades. Now we've identified a protein involved in targeted DNA demethylation, and we've also shown that it's critically important in reprogramming adult cells to function more like their stem cell predecessors."