The kinetics of MLL-PTD relapses was both significantly slower than those of MLL translocation positive ones (median doubling time: MLL-PTD: 24?d, MLL-translocations: 12?d, P?=?0??015, Wilcoxon rank sum test), and displayed greater variation depending on additional mutations.     ///    "As rapid relapses occurred in all MLL subgroups, frequent sampling are necessary to obtain acceptable relapse detection rates and times from molecular relapse to haematological relapse (blood sampling every second month: MLL-PTD: 75%/50?d. "