James Till

Until 2019, Till was an editorial member of the open access journal Journal of Medical Internet Research.

In the 1980s Till's focus shifted, moving gradually into evaluation of cancer therapies, quality of life issues, and Internet research, including Internet research ethics and the ethics of List mining.

In 1969, Till became a Fellow of the Royal Society of Canada.

In later work, Till & McCulloch were joined by graduate student Andy Becker. They cemented their stem cell theory and in 1963 published their results in Nature. In the same year, in collaboration with Lou Siminovitch, a trailblazer for molecular biology in Canada, they obtained evidence that these same marrow cells were capable of self-renewal, a crucial aspect of the functional definition of stem cells that they had formulated.

In the early 1960s, McCulloch and Till started a series of experiments that involved injecting bone marrow cells into irradiated mice. They observed that small raised lumps grew on the spleens of the mice, in proportion to the number of bone marrow cells injected. Till and McCulloch dubbed the lumps 'spleen colonies', and speculated that each lump arose from a single marrow cell: perhaps a stem cell.

He attended the University of Saskatchewan with scholarships awarded by the Standard Oil Company and the National Research Council, graduating with a B.Sc. in 1952 and a M.Sc. in physics in 1954. Some of his early work was conducted with Harold E. Johns, a pioneer in cobalt-60 radiotherapy. Till proceeded to Yale University, where he received a Ph.D. in biophysics in 1957. He then became a post-doctoral fellow at the University of Toronto.

James Edgar Till OC OOnt FRS FRSC (born August 25, 1931) is a University of Toronto biophysicist, best known for demonstrating – with Ernest McCulloch – the existence of stem cells.