Thanks partly to a new study, national guidelines now include a targeted treatment for melanomas with mutated KIT genes. The drug, called imatinib, is already used for chronic myelogenous leukemia. In a phase II clinical trial that included 12 people with melanomas that had KIT mutations, imatinib shrank tumors in 77%. KIT abnormalities can also include too many copies of this gene, but the drug was not effective against these tumors. KIT mutations, which are relatively uncommon, can occur in mucus membranes, extremities such as fingers, and skin with chronic sun damage. Now that there is a recommended targeted treatment, the researchers advise testing such melanomas for KIT mutations.