In acute promyelocytic leukemia (APL) with PML::RARα translocations and acute myeloid leukemia with KMT2A::MLLT3 (MLL::AF9) fusions, f-circRNAs can be oncogenic or sustain the oncogenic properties of chimeric proteins [18]. The gene discussed is KMT2A; the disease is acute promyelocytic leukemia.