Polycythemia VeraPolycythemiaThrombocythemia, EssentialHydroxyureaPrimary MyelofibrosisJanus Kinase 2Myeloproliferative DisordersPipobromanThrombocytosisJanus KinasesErythroid Precursor CellsAloeErythropoietinPyrazolesPhlebotomyReceptors, ThrombopoietinSplenomegalyErythropoiesisGranulocytesReceptors, ErythropoietinThrombosisBloodlettingHematocritAntisickling AgentsMutationErythroid CellsJanus Kinase 1Mutation, MissenseHematopoiesis, ExtramedullaryProtein Kinase InhibitorsAmino Acid SubstitutionPlatelet CountGPI-Linked ProteinsColony-Forming Units AssayThrombocytopeniaMegakaryocytesBudd-Chiari SyndromeLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeIsoantigensBone MarrowChromosomes, Human, 19-20ThrombopoietinHomozygoteHematopoietic Stem Cells