Sequential MRD monitoring during follow-up in t(8;21) patients. (A) Mantel-Byar estimate of relapse (%) in patients with > 500 RUNX1-RUNXITI copies in BM. (B) Mantel-Byar estimate of survival (%) from CR in patients with > 500 RUNX1-RUNXITI copies in BM. (C) Mantel-Byar estimate of relapse (%) in patients with > 100 RUNX1-RUNXITI copies in PB. (D) Mantel-Byar estimate of survival (%) from CR in patients with > 100 RUNX1-RUNXITI copies in PB.