Building 'smart' cell-based therapies

A technology for engineering human cells as therapies has been developed by scientists. The the technology becomes activated only in diseased tissues. It sits on the surface of a cell and can be programmed to sense specific external factors. For example, the engineered cell could detect big, soluble protein molecules that indicate that it's next to a tumor. When the biosensor detects such a factor, it sends a signal into the engineered cell's nucleus to activate a gene expression program, such a...