Myeloproliferative DisordersJanus Kinase 2Polycythemia VeraPrimary MyelofibrosisThrombocythemia, EssentialMyelodysplastic-Myeloproliferative DiseasesBone Marrow NeoplasmsReceptors, ThrombopoietinThrombocytosisLeukemia, Myelomonocytic, ChronicLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeLeukemia, Myelomonocytic, JuvenileAnemia, RefractoryMutationProto-Oncogene Proteins c-cblSplenomegalyMyelodysplastic SyndromesPhiladelphia ChromosomeJanus KinasesHematologic NeoplasmsMegakaryocyte Progenitor CellsSTAT5 Transcription FactorLeukemia, Myelogenous, Chronic, BCR-ABL PositiveHematologyLeukemia, Myeloid, AcuteClonal EvolutionHematopoietic Stem CellsBone MarrowFusion Proteins, bcr-ablBlast CrisisMutation, MissenseAmino Acid SubstitutionProtein Kinase InhibitorsGene Knock-In TechniquesMyeloid Progenitor CellsMegakaryocyte-Erythroid Progenitor CellsMyelopoiesisAnemia, SideroblasticDNA Mutational Analysis