Patient characteristics. Results of the EMC, EEC, PRV-1, and erythropoietin (EPO) assays and bone marrow histology are shown according to the percentage of total JAK2 represented by JAK2-V617F; inherited and acquired thrombophilia are also shown. ▪ indicates positive EMC and EEC assays, increased PRV-1 expression (defined as a PRV-1 cycle threshold [CT]/ABL CT ratio < 0.850), low serum EPO level (< 3.3 IU/L), presence of inherited or acquired thrombophilia, and bone marrow histology in favor of PV (panmyelosis; increased cellularity predominating on the erythroid lineage; megakaryocytes in clusters, pleiomorphic, with deeply lobulated nuclei) or in favor of ET (increased cellularity predominating on the megakaryocytic lineage; megakaryocytes in loose clusters or dispersed, large to giant, with abundant, mature cytoplasm and hyperlobulated nuclei, lacking dysplastic features; absence of fibrosis).⁸  □ indicates negative EMC and EEC assays, normal PRV-1 expression, normal or high serum EPO level, absence of inherited or acquired thrombophilia, and normal bone marrow histology results. Empty spaces mean that the assay was not performed or that the results were not available.