Interestingly, JAK2 has been identified to be involved in two rare translocations: with ETV6, at 12p13, in acute lymphoblastic leukemia and rarely myeloproliferative (CML-like) disorder [4,10] and with BCR, at 22q11.2, in patients with chronic myeloid leukemia [11]. This evidence concerns the gene JAK2 and acute lymphoblastic leukemia.