The translocation of t(3;21)(q26;q22) results in the fusion of MECOM with RUNX1 and has been reported in a pediatric patient with acute myelomonocytic leukemia [81], acute monoblastic leukemia [82], and secondary MDS/AML after treatment for T-cell ALL [83]. This evidence concerns the gene RUNX1 and acute myeloid leukemia.