In an unusual disease known as Bloom syndrome, patients exhibit an extremely high incidence of cancers in many tissues. In fact, some experts consider Bloom syndrome to be among the most cancer-prone hereditary diseases known. Although the illness is rare, it fascinates scientists since it can teach them more about how cancers arise and how the body normally suppresses them. Information gleaned from studies of the syndrome should provide insights into other forms of cancer, they say. Now, working with fruit flies on the gene which, when mutated, causes Bloom syndrome in humans, scientists at the University of North Carolina at Chapel Hill have discovered more about the key mechanisms by which DNA inside cells is repaired.