These studies demonstrated that high methylation subgroups were highly correlated with most of the established JMML risk factors, including older age10,11, higher hemoglobin F (HbF)10,11, lower platelet count10,11, PTPN11/NF1 mutations6,12, the presence of secondary genetic events13,14, LIN28B overexpression15, and an AML-like expression profile16, and the high methylation subgroups were also associated with poor survival17,18. This evidence concerns the gene PTPN11 and juvenile myelomonocytic leukemia.