After the breakthrough discovery of oncogenic f-circRNAs in leukemia with KMT2A::MLLT3 (MLL::AF9) [18], followed by the finding of f-circRNAs in other malignancies with different translocations [19–22], no data emerged about chimeric circRNAs in leukemias with other rearrangements involving the KMT2A gene. Here, MLLT3 is linked to leukemia.