In November 2007 scientists announced they had developed a new way to cause mature human cells to resemble pluripotent stem cells - similar in many ways to human embryonic stem cells. By simply altering the expression of just four genes using genetic modification, the mature cells were 'induced' to become more primitive, stem cells and were referred to as 'induced' pluripotent stem (iPS) cells.

Initially iPS cells were generated using viruses to change gene expression, however since the initial discovery, technologies for reprogramming cells are moving very quickly and researchers are now investigating the use of new methods that do not use viruses which can cause permanent and potentially harmful changes in the cells. If they are able to be made safely, and on a large scale, iPS cells could possibly be used to provide a source of cells to replace cells damaged following illness or disease. It may even be possible to make stem cells for therapy from a patient's own cells and thereby avoid the use of anti-rejection medications.

However, right now scientists are using this method to create disease specific cells for research by taking a cells - maybe from a skin biopsy - from a patient with a genetic disorder, such as Huntington’s disease, and then using the iPS cells to study the disease in the laboratory. Scientist hope that such an approach will help them understand the development and progression of certain diseases, and assist in the development and testing of new drugs to treat disease.

While the discovery of iPS cells was a very important development, more research needs to be done to discover if they will offer the same research value as embryonic stem cells and if they will be as useful for therapy.

To learn more about iPS cells watch What are induced pluripotent stem cells? in our video library.