The excitement of gene-hunting was described last week by Mike Stratton of the Institute of Cancer Research, whose team recently won an international race to isolate the breast cancer gene, BRCA2. "The number of rumours that go round about genes like this are enormous. I received four phone calls telling me it had been isolated by one of the competing labs. The mood went up and down," he said, "but we knew that being British we could be gracious losers."