FLT3 and acute myeloid leukemia: Based on these findings NPM1mut AML was included as an entity in the World Health Organization classification 2016 and the NPM1mut/FLT3-ITD genotypes stratified by the ITD allelic ratio were integrated in the risk stratification of the European LeukemiaNet (ELN) recommendations, subdividing AML in subsets with highly distinct prognosis2–4.