Availability of the newer and more sensitive technology to quantify the level of leukemic burden has definitively favored the use of MRD in AML; in particular, in selected genetic subtypes, such as CBF-AML and NPM1, mutated AML, molecular monitoring of patients in morphologic CR allows identification of those patients deemed at high risk for disease relapse, ultimately resulting in a further improvement of clinical outcome [39,40]. This evidence concerns the gene NPM1 and acute myeloid leukemia.