Of the 134 patients for whom sequence data was obtained, 44 (33%) had tumours harbouring activating mutations in KRAS, BRAF, or NRAS. Mutations were detected in 22 (31%) of 70 patients in the trametinib group and in 22 (34%) of 64 patients in the standard-of-care group. The gene discussed is KRAS; the disease is neoplasm.