Larry Donehower (Division of Molecular Virology, Baylor College of Medicine, Houston): "The p53 tumor suppressor gene has recently received a great deal of attention because its loss or mutation occurs in more than half of all human tumors. Despite all this attention, the normal role of p53 in regulating cellular processes is only beginning to be understood.
"The work described in this paper was an attempt to provide insights into the role of p53 in mammalian development and tumorigenesis by a `knockout' of the gene in the mouse germ line using some of the novel gene-targeting techniques that our collaborator Allan Bradley had developed.
"Our hypothesis was that knockout mice missing both normal p53 alleles would die early in their development, since it had been known that p53 had important effects on the cell cycle. In fact, the surprising result was that these null p53 mice appeared normal in every ...
