*Treatment modifications depending on these measurements are strongly recommended to be based on at least 2 analyzed samples.

†Time points should be specified within the respective protocol. At least one relevant treatment element should be administered in between.

‡MRD reappearance can be equated to “MRD relapse” (which would then be considered “event”) if a particular ALL protocol has provided unequivocal evidence that MRD reappearance is closely associated with hematological relapse.