CD34 and primary myelofibrosis: Methods: Two gene expression datasets of CD34+ hematopoietic stem and progenitor cells (HSPCs) from patients with JAK2V617F+ myeloproliferative neoplasm (MPN) [n = 66, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)] and healthy controls (HC) (n = 30) were acquired from the GEO (Gene Expression Omnibus) database.