Dr Yamanaka, who also serves as a senior investigator at the Gladstone Institute of Cardiovascular Disease in San Francisco, and his research team generated iPS cells by introducing four genes - Oct3/4, Klf4, Sox2 and c-Myc - into somatic cells for the first time in the world. iPS cells, like embryonic stem cells, are capable of growing robustly and differentiating into any type of cells in the human body. He announced the generation of mouse iPS cells in 2006 and human iPS cells in 2007.

He was born in Osaka, Japan, in 1962 and obtained his MD in 1987 at Kobe University and trained as an orthopaedic surgeon before switching to basic research. Dr Yamanaka received his PhD at Osaka University in 1993, after which he worked at the Gladstone Institute in San Francisco and Nara Institute of Science and Technology in Japan.

"Winning the prize would be not only a tremendous honor for me, but also a powerful encouragement for myself, my colleagues, and all the scientists working with iPS cells to continue research activities," Dr Yamanaka was quoted as saying in a CiRA press release put out after the names of the winners were declared by the Nobel Assembly at Karolinska Institutet. "I will work harder with my colleagues to develop effective drugs and new therapy for intractable diseases using patient-derived iPS cells."

Sir John B Gurdon was born in 1933 in Dippenhall, UK. He received his doctorate from the University of Oxford in 1960 and was a postdoctoral fellow at California Institute of Technology. He joined Cambridge University, UK, in 1972 and has served as Professor of Cell Biology and Master of Magdalene College.