The CALM/AF10 fusion gene derived from the t(10;11)(p13;q14) chromosomal translocation can be found in T-cell acute lymphoblastic leukemia (T-ALL), acute myeloid leukemia (AML) and mixed phenotype acute leukemia (MPAL) of T/myeloid lineages (1–5). This evidence concerns the gene MLLT10 and T-cell acute lymphoblastic leukemia.