Theodor Boveri and the origin of malignant tumours.

As long ago as 1914, Theodor Boveri suggested that there is an inhibitory mechanism in every normal cell that prevents the process of cell division until the inhibition has been overcome by a special stimulus. From his work on abnormal mitoses in the eggs of echinoderms, Boveri also suggested that the inhibitor resided in the chromosomes. The relevance of Boveri's ideas to modern cancer research is discussed in this Retrospective article.