James Thomson. Portrait of James Thomson, developmental biologist at the University of Wisconsin-Madison, USA. In 1998, his research group reported the first successful culture of human embryonic stem (ES) cells. ES cells are the parent cells that give rise to all of the cell types in the human body. Thomson's group grew ES cells taken from donated embryos and produced a range of cell types from them. This technology provides the potential for the mass production of human cells in the laboratory. The transplantation of healthy cells into patients could offer a cure for many degenerative diseases and some cancers.