BCR-ABL DNA evidence of residual disease in patients with UMRD. (A) Results of BCR-ABL DNA monitoring for 13 patients in TFR. Solid triangles indicate that BCR-ABL DNA was detected; open triangles indicate that BCR-ABL DNA was not detected. The horizontal line shows the current period of follow-up for each patient. An arrow at the end of the line indicates that the patient remains in stable TFR with follow-up of more than 5 years. (B) The average level of BCR-ABL DNA for 13 patients who met the study definition of molecular relapse showing all results from patients with UMRD at study entry, all results at molecular relapse, and all results after regaining UMRD on IM re-treatment. Quantitative results are expressed relative to the individual patient’s baseline diagnostic sample. NS, not significant.