An experimental drug may strengthen treatments that target melanomas with mutations in the BRAF gene, reported researchers from the pharmaceutical company Merck at the American Association for Cancer Research's 2013 meeting. Treatments that target BRAF often stop working because tumors activate a related protein called ERK, which is the target of Merck's new drug. Called SCH772984, the drug inhibits ERK in cultured human tumor cells with BRAF, NRAS, or KRAS mutations; slows cell division in human tumor cells that resist treatments that target BRAF or MEK; and shrinks tumors in mice. The researchers have begun a phase I clinical trial of an ERK inhibitor in people with tumors.