Response to retreatment with IM after molecular relapse. Four years of follow-up after molecular relapse is shown. The number of evaluable patients at each time point is shown at the top of the column. Because of the smaller number of observations at later time points, the data after 12 months are grouped to show the 3 months prior to the stated time point (ie, results for 15 months are all results for the interval 13-15 months). If a patient had two qRT-PCR results in an interval, the patient is scored only once with the highest recorded BCR-ABL level.