This method is used by CDI for the creation of its iCell(R) and MyCell(R) Products. This episomal reprogramming patent has a term extending through May 2030. Episomal vectors used in reprogramming are circular pieces of DNA that, when introduced into adult tissue cells, express genes known as reprogramming factors that drive the adult tissue cells back to a stem cell state, before then exiting the cell. This non-integrating methodology alleviates major safety concerns over the potential use of iPS-derived cells as therapeutics and removes a significant barrier for applying the technology in a clinical setting. Episomal reprogramming already has been performed to Good Manufacturing Practice (GMP) standards, a prerequisite for use of these cells in clinical applications. In comparison, the original reprogramming method, published in 2007, uses viral vectors to insert four genes into the adult tissue cell's DNA. These genes integrate directly into the cell's genome.