Polycythemia VeraPolycythemiaThrombocythemia, EssentialJanus Kinase 2Primary MyelofibrosisMyeloproliferative DisordersThrombocytosisPipobromanErythroid Precursor CellsErythropoietinPhlebotomyErythropoiesisReceptors, ThrombopoietinReceptors, ErythropoietinHematocritAloeGranulocytesBloodlettingThrombosisHydroxyureaHematopoiesis, ExtramedullaryMutation, MissenseMutationGPI-Linked ProteinsVon Hippel-Lindau Tumor Suppressor ProteinAmino Acid SubstitutionErythroid CellsHomozygotePlatelet CountIsoantigensColony-Forming Units AssayMegakaryocytesErythrocyte VolumeBudd-Chiari SyndromeBone MarrowSomatostatinomaRussiaLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeChromosomes, Human, 19-20ThrombopoietinLeukocytosisHematopoietic Stem CellsSplenomegaly