Blood drawn with a simple needle stick can be coaxed into producing stem cells that may have the ability to form any type of tissue in the body, three independent papers report in the July 2 Cell Stem Cell. The new technique will allow scientists to tap a large, readily available source of personalized stem cells. Because taking blood is safe, fast and efficient compared to current stem cell harvesting methods, some of which include biopsies and pretreatments with drugs, researchers hope that blood-derived stem cells could one day be used to study and treat diseases — though major safety...