In this study, 53 patients with AML or MDS in CR with positive MRD by either a RT-qPCR-trackable molecular aberration (≥ 1% mutant NPM1, RUNX1-RUNX1T1, CBF-MYH11, or DEK-NUP214) or decreased donor CD34 chimerism ≤ 80% by MFC (in patients who were post-HSCT) were treated with azacitidine. This evidence concerns the gene RUNX1 and acute myeloid leukemia.