Now that we know how to turn adult, differentiated cells back into stell cells, we have an idea how to control the rate at which they produce new cells:

In most organs of the body, old cells are continually being replaced by new. If too many new cells are produced, however, it can lead to overgrowth and tumour formation. Too few cells, on the other hand, can result in organ degeneration. It is therefore crucial that exactly the right number of cells are produced.

As many serious disorders cause a reduction in the production of new cells, scientists are keen to develop drugs that stimulate the process, which in turn could help the body to cure itself.

It has long been known that the new cells are often formed by immature cells known as stem cells, but the mechanism regulating the number of new cells produced has remained something of a mystery. However, in a new study to be published by Cell stem-cell researcher Jonas Frisén has succeeded in showing how the body’s own stem cells do just this. Working alongside an American group of researchers, Professor Frisén and his team have identified a signal transduction process that regulates the degree of stem-cell division.