The Wellcome Trust congratulates Professor Sir Martin Evans, who has been named joint winner of the 2007 Nobel Prize in Physiology or Medicine for his pioneering work on the genetic modification of embryonic stem cells.

This work, and that of his fellow 2007 Nobel Laureates - Dr Mario Capecchi from the University of Utah and Dr Oliver Smithies from the University of North Carolina at Chapel Hill - enabled embryonic stem cells to be used to create animal models of human diseases, a field that transformed biomedical science and continues to have a huge impact on the study of health and disease today.

The Wellcome Trust has supported Professor Evans's research extensively over his career, including funding of £2.3 million for research into the genetic manipulation of embryonic stem cells at the University of Cambridge from 1988 to 1998, and £2.4m to establish the Henry Wellcome Laboratories for Mammalian Post-Genomic Analysis at the University of Cardiff.

In his research, Professor Evans showed that it was possible to isolate embryonic stem cells - which have the potential to develop into any cell type seen in the adult animal - from mice and grow them in culture in the lab. He then developed a technique involving these cells that allowed researchers to manipulate the genetic make-up of mice.

The work of Evans, Capecchi and Smithies led to the development of a technology called gene targeting, which is widely used in biomedical research and permits so-called 'knock-out' experiments, where single genes can be inactivated. Around 10 000 mouse genes (approximately half of the genome) have been knocked out to date, and gene targeting has produced over 500 different models of human disorders, including cancer, diabetes and neurodegenerative disorders.

Image: Human embryo revealing the inner cell mass; Yorgos Nikas