In addition, several mutations on the genes functioning as epigenetic modifiers and splicing factors were identified not only in leukemias/myelodysplastic syndromes but also in BCR::ABL1-negative MPNs, and the association of these mutations with the prognosis of BCR::ABL1-negative MPNs has been analyzed (Figure 2C) [14,15,16,17]. The gene discussed is BCR; the disease is leukemia.