In a recent study focussing on characterization of serial samples from JMML patients at diagnosis and then beyond through relapse and transformation to AML, mutations were found in NF1, NRAS, KRAS, PTPN11 or CBL in 85% of patients, as well as recurrent mutations in other genes involved in signal transduction, splicing, PRC2 and transcription. This evidence concerns the gene KRAS and acute myeloid leukemia.