Ten years ago, when the draft of the human genome was announced, doctors never tested for genetic mutations within their patients, making it impossible to diagnose certain diseases or even to determine why certain medications were working for a specific patient and others weren't. Today, says New Scientist's Bijal Trivedi, medicine is undergoing a "revolution" because of genomics. Pharmacogenomics would have been impossible 10 years ago, Trivedi says, as would testing IVF embryos for specific genetic mutations, something that is routinely done now. Cancer patients are also routinely tested for mutations. "About a third of breast cancers have mutations that result in the overproduction of the HER protein, which can be treated by an antibody called trastuzumab that blocks HER's effect," Trivedi says. "Testing ensures patients do not suffer nasty side effects pointlessly, and also saves a lot of money." Doctors still need time to learn how to interpret the results of genetic tests, however, and it could be a while before genetic tests are routinely ordered before any drug is prescribed. "It's going to be a slow revolution," Trivedi adds, "but it is under way."