Our organs are made up of different cell types, specialised according to their function in the body. The cells of the early embryo - embryonic stem cells - possess the ability to develop into almost any type of cell, called pluripotency. As a cell specialises, its capacity to produce different cell types - its potential - decreases. Specialisation, and the loss of potential, is typically a one-way process. However, in 2006 scientists developed the technology to 'reverse' a cell's specialisation, restoring its potential. These pluripotent stem cells may be used in therapy, or may be induced to specialise as a new cell type.
Scientists are optimistic that reprogramming could overcome some of the major issues associated with cell therapy: cells could be derived from the patient, avoiding both the need for a donor and the risk of immune rejection. However, the long-term stability and safety of these cells remains to be studied in a therapeutic context.