Polycythemia VeraPolycythemiaThrombocythemia, EssentialJanus Kinase 2Primary MyelofibrosisMyeloproliferative DisordersSpleenPipobromanThrombocytosisErythroid Precursor CellsAloeErythropoietinPhlebotomyReceptors, ThrombopoietinErythropoiesisGranulocytesReceptors, ErythropoietinThrombosisHydroxyureaHematocritBloodlettingHematopoiesis, ExtramedullaryMutation, MissenseMutationErythroid CellsAmino Acid SubstitutionGPI-Linked ProteinsPlatelet CountMegakaryocytesSplenomegalyColony-Forming Units AssayBone MarrowIsoantigensBudd-Chiari SyndromeLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeHematopoietic Stem CellsChromosomes, Human, 19-20ThrombopoietinHomozygote