Since the initial description of Yamanaka and Takahashi in 2006, the generation of induced pluripotent stem cells (iPSCs) has become a widely used method [1]. As human iPSCs are generated without the destruction of an embryo, the disadvantage of broad ethical concerns is diminished. However, the most important advantage of iPSCs compared to ESCs (embryonic stem cells) is the possibility to use mature somatic cells from patients who suffer from genetically defined diseases [2–4]. The obtained iPSCs exhibit the donor's specific genetic changes, opening the possibility to characterize specific phenotypes in patient derived stem cells and their differentiated progeny. The so-obtained differentiated disease specific cells could also be used for drug screenings to find substances which specifically diminish or revert observed phenotypes. These characteristics could pose a powerful tool to better understand a disease pathomechanism [5] and might serve for future therapeutic approaches (reviewed in [6]). The future benefit for patients is that, in transplantation, autologous stem cells, differentiated cells, and even stem cell derived tissues show no relevant graft-versus-host disease.
