One of the chief concerns about the clinical application of stem cells to cell therapy is the safety of the cells after they are transplanted. This research program addresses safety bottlenecks that are common to all stem cell-based therapies. We have two general goals. The first goal is to generate a set of methods that can be used to rid populations of cells to be transplanted of any contaminating stem cells that might be capable of forming tumors. The second goal is to develop methods to identify and purify the cell type that is most likely to be therapeutic. Over the second year of this joint California/Victoria partnership the research has progressed according to the plans described in the grant application and all millestones have been met.