Four different response patterns defined according to the MRD values as assessed by RQ-PCR. Examples of individual patients are shown in panel A for good response, in panel B for good response and later relapse, which was detectable early as the result of increasing levels of the NPM1 mutation, in panel C for patients with less than 3-log reduction and relapse, and in panel D for patients with persistent disease. X-axis indicates time in days; y-axis indicates mutation level given as %NPM1/ABL1.