• Meet the 2016 WHO diagnostic criteria for ET (Essential Thrombocythemia) and PV (Polycythemia Vera)

‣ ET (Essential Thrombocythemia) major criteria:

∙ Platelet count \> 450 \* 10\^9/L; (2) Bone marrow biopsy shows marked megakaryocytic proliferation with increased mature megakaryocyte volume and increased nuclear lobulation. There is no significant granulocytic proliferation, left shift, or erythroid proliferation, with grade 1 fibrosis observed in a few cases; (3) Does not meet the WHO diagnostic criteria for BCR-ABL1+ CML, PV, PMF, MDS, or other myeloproliferative neoplasms; (4) JAK2, CALR, or MPL mutation positive.

∙ Secondary criteria: (1) Presence of a clonal marker or absence of evidence for reactive thrombocytosis.

∙ The diagnosis of ET requires the fulfillment of all four main criteria, or the first three main criteria plus one secondary criterion.

⁃ PV (Polycythemia Vera) main criteria: (1) Hemoglobin \> 16.5 g/dL in males, \> 16 g/dL in females, or Hematocrit \> 49% in males, \> 48% in females, or an increase in red cell volume of 25% or more above the normal value; (2) Bone marrow biopsy shows increased cellularity inappropriate for age, with marked erythroid, granulocytic, and megakaryocytic proliferation, and the presence of mature megakaryocytes of varying sizes and morphologies; (3) JAK2 V617F mutation positive or JAK2 exon 12 mutation positive.

• Secondary criteria: Serum Epo (Erythropoietin) level below the lower limit of the normal range.

• The diagnosis of PV requires the fulfillment of three major criteria, or the first two main criteria plus one secondary criterion.

• For ET patients, the criteria for cytoreductive therapy must be met, as follows:

• (1) For patients without a history of thrombosis: Age ≥ 60 years, regardless of the presence of cardiovascular risk (CVR) or JAK2V617 mutation; Any age with a platelet count \> 1500 × 109/L. (2) For patients with a history of arterial thrombosis: Any age, regardless of the presence of CVR and JAK2V617 mutation; (3) For patients with a history of venous thrombosis: Any age, regardless of the presence of CVR and JAK2V617 mutation; 3.ECOG score ≤ 2. 4.Cardiac ejection fraction (EF) ≥ 60%. 5.The participant voluntarily signs the informed consent form.