These data therefore also underscore the current guidelines for diagnosis of chronic myelomonocytic leukemia, other myelodysplastic/myeloproliferative neoplasms and myeloproliferative neoplasms unclassified that the primary genetic work-up should not only exclude BCR::ABL1 positive chronic myeloid leukemia but also cases of MLN-TK. The gene discussed is TKT; the disease is chronic myelomonocytic leukemia.