Primary MyelofibrosisPolycythemia VeraPolycythemiaJanus Kinase 2Thrombocythemia, EssentialMyeloproliferative DisordersSplenomegalyThrombocytosisReceptors, ThrombopoietinJanus KinasesPyrazolesPipobromanBone MarrowMyelodysplastic-Myeloproliferative DiseasesMegakaryocytesSea-Blue Histiocyte SyndromeMutationErythroid Precursor CellsHematopoiesis, ExtramedullaryAloeJanus Kinase 1ErythropoietinPlatelet CountMutation, MissensePhlebotomyAmino Acid SubstitutionErythropoiesisProtein Kinase InhibitorsPrognosisThrombocytopeniaKaryotypingGranulocytesHydroxyureaThrombosisWorld Health OrganizationReceptors, ErythropoietinThrombopoietinBloodlettingHematocritReticulinDisease ProgressionErythroid CellsClinical Trials, Phase III as TopicDrug ApprovalLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeHematopoietic Stem Cells