Polycythemia VeraPolycythemiaHydroxyureaThrombocythemia, EssentialJanus Kinase 2Primary MyelofibrosisMyeloproliferative DisordersPipobromanThrombocytosisErythroid Precursor CellsAloeErythropoietinPhlebotomyAntisickling AgentsReceptors, ThrombopoietinErythropoiesisGranulocytesFamily PracticeThrombosisReceptors, ErythropoietinBloodlettingHematocritMutationErythroid CellsMutation, MissensePlatelet CountHematopoiesis, ExtramedullaryAmino Acid SubstitutionGPI-Linked ProteinsColony-Forming Units AssayAnemia, Sickle CellMegakaryocytesLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeBudd-Chiari SyndromeBone MarrowIsoantigensFetal HemoglobinHomozygoteSplenomegalyChromosomes, Human, 19-20Physician's Practice PatternsThrombopoietinHematopoietic Stem Cells