Induced pluripotent stem cells (iPS) — those derived from adult cells — are inching closer to the clinic. But as a new study helps to show, much work remains before the field can yield mainline treatments. The older a patient is, the more likely it is that induced pluripotent stem (iPS) cells derived from them will carry genetic mutations that could affect the cells' function, researchers report. These mutations are found in the DNA of mitochondria, organelles that power the cell and have their own genomes. Each cell can contain hundreds of mitochondria. http://www.nature.com/news/mutated-mitochondria-could-hold-back-stem-cell-therapies-1.19752
