Polycythemia VeraHematopoiesisPolycythemiaPhosphoglycerate KinaseThrombocythemia, EssentialJanus Kinase 2Primary MyelofibrosisMyeloproliferative DisordersHematopoiesis, ExtramedullaryThrombocytosisPipobromanErythroid Precursor CellsErythropoietinAloeErythropoiesisPhlebotomyHematopoietic Stem CellsReceptors, ThrombopoietinGranulocytesColony-Forming Units AssayReceptors, ErythropoietinBone MarrowThrombosisErythroid CellsHydroxyureaHematocritBloodlettingMegakaryocytesHematopoietic SystemMutationMutation, MissensePlatelet CountAmino Acid SubstitutionGPI-Linked ProteinsBone Marrow CellsSplenomegalyBudd-Chiari SyndromeHomozygoteAntigens, CD34IsoantigensLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeChromosomes, Human, 19-20ThrombopoietinLeukocytosisProto-Oncogene ProteinsLeukemia