In patient #2, 2nd line treatment with dasatinib resulted in a sustained remission of the BCR::ABL1 fusion (BCR::ABL1IS < 2%) and was stopped after 6 months due to progression into MPN blast phase with a complex aberrant karyotype and massive increase of the JAK2 V617F VAF (66%). The gene discussed is BCR; the disease is myeloproliferative neoplasm.