NPM1 and acute myeloid leukemia: The European Leukemia Net (ELN) MRD Working Group recommends the use of specific fusion genes (RUNX1-RUNX1T1, CBFB-MYH11 and PML-RAR) or the mutated gene NPM1 (one of the most frequent genetic aberrations in AML), which are strong predictors of relapses and can be detected with high sensitivity (up to 10−6) by RT-qPCR [28, 32].