Two patients were successfully rechallenged after progression with vemurafenib or dabrafeib+trametinib [78], and a melanoma patient in which vemurafenib induced proliferation of a previously undetected NRAS-mutant chronic myelomonocytic leukemia was successfully treated using an adjusted intermittent schedule of vemurafenib guided by changes in white cell counts [79]. This evidence concerns the gene NRAS and chronic myelomonocytic leukemia.