TEL(ETV6)-JAK2 fusion genes have been identified in both ALL and atypical chronic myelogenous leukemia (aCML), with slightly different translocations driving each, t(9;12)(p24;p13) and t(9;15;12)(p24;q15;p13), respectively (Peeters et al., 1997). This evidence concerns the gene JAK2 and acute lymphoblastic leukemia.