In addition to MLN-eo-TK, JAK2 rearrangements can also be found in BCR::ABL1-negative myeloproliferative neoplasms (MPN), myelodysplastic neoplasms (MDS), MDS/MPN overlap syndromes, B/T lymphomas, acute myeloid (AML), lymphoblastic (ALL) or mixed- phenotype acute leukemia (MPAL) [9, 10]. The gene discussed is BCR; the disease is mixed phenotype acute leukemia.