NPM1 and acute myeloid leukemia: Numerous studies suggested a somewhat lower MRD burden in PB, but a good correlation between PB and BM MRD, e.g., in MFC [72,73] or qRT-PCR assays for CBF-AML [16,74,75] and NPM1-mutated AML [14,15,59] or similar percentages of MRD-positive patients in NGS [61].