Loading...
Embryonic stem cells (ESCs) offer the promise of replacing cells that have been killed by disease. But applying ESCs to therapy requires surmounting two large obstacles. First, because we can’t turn back the clock, if a patient needed ESCs for therapy, they would have to come from an embryo that was genetically different from the patient and, therefore, might provoke immune rejection. Second, some people have strong ethical objections to use of human embryos for medical purposes.
Retroviruses that carry four genes into differentiated adult cells (easily obtainable skin fibroblasts) transform those cells into induced pluripotent stem (iPS) cells that seem to have all the features and therapeutic potential of ESCs. This landmark discovery (JW …