Polycythemia VeraPolycythemiaHydroxyureaThrombocythemia, EssentialJanus Kinase 2Primary MyelofibrosisMyeloproliferative DisordersPipobromanThrombocytosisErythroid Precursor CellsAloeErythropoietinPhlebotomyAntisickling AgentsReceptors, ThrombopoietinErythropoiesisGranulocytesReceptors, ErythropoietinThrombosisBloodlettingHematocritMutationErythroid CellsMutation, MissenseHematopoiesis, ExtramedullaryPlatelet CountAmino Acid SubstitutionGPI-Linked ProteinsColony-Forming Units AssayAnemia, Sickle CellMegakaryocytesLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeBudd-Chiari SyndromeBone MarrowIsoantigensFetal HemoglobinSplenomegalyChromosomes, Human, 19-20HomozygoteThrombopoietinHematopoietic Stem Cells