KMT2A and acute lymphoblastic leukemia: It is also accepted in KMT2A-rearranged infant ALL, that MRD testing based on detection of this disease related fusion is not only feasible, but also preferable to Ig/TCR markers given the high incidence of oligoclonality and earlier stage of cell of origin that characterises ALL with translocations of the KMT2A gene (previously known as MLL) [8, 9].