MLLT3 and leukemia: M4 represents acute myelomonocytic leukemia [15,16], while M5, or monocytic leukemia, often presents with poor prognosis, extramedullary disease, and abnormalities on chromosome 11q, including the MLLT3 (MLL-AF9) fusion protein, causing the Mixed-Lineage Leukemia (MLL) subtype [17,18,19,20].