His diabetes work led him to understand how to create a drug that would get directly into cancercells, which were a lot like the stemcells he was studying in diabetes.
Eggan's technique, which is the subject of a paper in the current issue of Nature, creates stemcells specific to a particular disease, likecancer or diabetes, without a supply of human egg cells.
Like natural selection and germs, the discovery of cancerstemcells illustrates how the most fruitful scientific findings are often not those of individual experiments, however intriguing, but those that organise knowledge into theory.