Leading article: The mouse that roared

Next time you read about a potential medical breakthrough involving stem cells or gene therapy, remember that it might not have been possible without the work of individuals such as Sir Martin Evans and Professor Mario Capecchi, whose remarkable life story we outline today.

Sir Martin, Professor of Mammalian Genetics at Cardiff University, is one of the founders of stem cell research. In the late 1970s he demonstrated that cells taken from a mouse embryo could be removed and grown separately in a laboratory. Meanwhile, Professor Capecchi from the University of Utah and Professor Oliver Smithies from the University of North Carolina developed a technique whereby these stem cells could be genetically altered in the lab then injected back into a mouse embryo to create offspring with altered DNA. This was a significant breakthrough because they could now deactivate or modify particular genes in mice. These mouse "models" have, in turn, allowed scientists to study how genes affect hereditary human diseases.

Now the three men have been awarded the Nobel Prize for medicine. It is a welcome judgement. Their work has been of enormous benefit to medical science. The scientists' genetically modified rodents are now the universal test-bed for all areas of biomedicine, from basic research into human diseases to the development of new treatments. Indeed, their work is one of the reasons the number of medical experiments on animals has risen in recent decades. Their research has helped to demonstrate why some diseases such as cystic fibrosis strike humans at a cellular level. It has provided new insights into conditions such as cancer and heart disease. New light has been shed on the ageing process and the way an embryo develops in the womb.

Many congratulations are in order to the three scientists. And the success of Sir Martin, in particular, is more evidence that Britain punches above its weight in the world of cutting-edge scientific research. But we cannot afford to rest on our laurels. This prize was awarded for research that dates back some 30 years. And the situation is significantly less rosy in the world of British science today. There are substantially fewer young people applying to study serious science courses. University physics and chemistry departments have been closing at an alarming rate.

If we want to maintain our strong position, the Government will need to develop some better incentives for young people to enter the world of scientific research. As well as honouring our outstanding figures of the present, we need to encourage the Nobel Prize winners of the future.