Sequential MRD monitoring in an allogeneically transplanted patient. De novo AML patient is characterized by a CD34⁺ population (A) with an aberrant expression of CD56 (B). Three days before transplantation, the percentage of MRD is high (0.7%) which is known to be highly predictive for a fast relapse; 38 days after allogeneic transplantation, the percentage of MRD has dropped down to 0.01%, but unfortunately rises to 2.3% at day 108 after transplantation. Stopping immune suppression at that time point led to a quick decrease of MRD in the next months (0.04% at days 131 and 203), probably due to the graft-versus-leukemia effect resulting from discontinuation of immune suppression.