MPN PROGRESSion Registry: Observational Study Tracking Symptoms, Treatments, and Disease Progression in People With Myeloproliferative Neoplasms (MPNs)

Inclusion Criteria: * Adults aged 18 years or older at the time of enrollment. * Confirmed diagnosis of a myeloproliferative neoplasm (MPN), including one or more of the following subtypes, according to WHO 2022 criteria, including patients originally diagnosed with one of these conditions but who have received one or more stem cell transplants (SCTs) or bone marrow transplants (BMTs): * Polycythemia vera (PV) * Essential thrombocythemia (ET) * Primary myelofibrosis (PMF) * Secondary myelofibrosis (post-ET or post-PV MF) * Pre-fibrotic primary myelofibrosis (pre-PMF) * Myeloproliferative neoplasm-unclassifiable (MPN-U) * Myeloproliferative neoplasm, accelerated phase (MPN-AP) * Myeloproliferative neoplasm, blast phase (MPN-BP) * Post-MPN acute myeloid leukemia (AML) * Myelodysplastic syndrome (MDS)/MPN overlap syndrome * Myeloproliferative neoplasm, blast phase (MPN-BP) * Ability to provide informed consent electronically or through a legally authorized representative. * Willingness to share health information, including electronic health records (EHR), laboratory values, and survey responses. * Willingness to complete periodic patient-reported outcome (PRO) surveys and symptom tracking assessments. Exclusion Criteria: * Individuals under 18 years of age. * Inability to provide informed consent, either directly or through a legally authorized representative. * Currently enrolled in an interventional clinical trial where participation would interfere with the ability to participate in this observational registry (based on investigator or sponsor judgment). * Any condition that, in the judgment of the study team, would make participation in the registry infeasible or unsafe.