The (8;21) translocation, which is associated with 40–80% of M2 subtype of AML and 12–20% of all cases of AML, involves the AML1 (RUNX1) gene on chromosome 21, and the eight-twenty-one (ETO) gene on chromosome 8 (Zhou et al., 2007). The gene discussed is RUNX1; the disease is acute myeloid leukemia.