"In an approach that many doctors and scientists hope will form the medical care of the future, Massachusetts General Hospital in Boston has for the past year and a half been offering people with cancer a novel diagnostic test. Instead of assessing tumours for a single mutation that will indicate whether a drug is likely to work or not, the hospital tests patients for some 150 mutations in more than a dozen cancer-causing genes, with the results being used to guide novel treatments, clinical trials and basic research. This form of personalized medicine tailors treatments on the basis of the molecular and genetic characteristics of a patient's cancer cells, potentially improving the treatment's outcome."