Polycythemia VeraPolycythemiaPrimary MyelofibrosisHydroxyureaJanus Kinase 2Janus KinasesThrombocythemia, EssentialPyrazolesMyeloproliferative DisordersSplenomegalyJanus Kinase 1PipobromanThrombocytosisProtein Kinase InhibitorsErythroid Precursor CellsAloeErythropoietinPhlebotomyAntisickling AgentsThrombocytopeniaReceptors, ThrombopoietinClinical Trials, Phase III as TopicIntention to Treat AnalysisErythropoiesisDrug ApprovalClinical Trials, Phase I as TopicGranulocytesClinical Trials, Phase II as TopicReceptors, ErythropoietinThrombosisBloodlettingHematocritSpleenMutationErythroid CellsFollow-Up StudiesMutation, MissenseHematopoiesis, ExtramedullaryPlatelet CountAmino Acid SubstitutionTreatment OutcomeGPI-Linked ProteinsColony-Forming Units AssayAnemia, Sickle CellOrgan SizeMegakaryocytesLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeBudd-Chiari SyndromeBone MarrowIsoantigensFetal HemoglobinChromosomes, Human, 19-20HomozygoteThrombopoietinHematopoietic Stem Cells