Polycythemia vera (PV) is a myeloproliferative neoplasm (MPN) characterized by hyper-proliferation of the erythroid, megakaryocytic and granulocytic lineages and the presence of an activating mutation in JAK2. To elucidate mechanisms that regulate PV stem cells, we applied a newly developed data-independent acquisition (DIA) mass spectrometry (MS) technology to purified hematopoietic stem and progenitor cell (HSPC) subpopulations of patients with chronic and progressed PV. Proteomic analyses were supplemented by RNA-sequencing (RNA-seq) and identified targets validated by flow cytometry and functional in vitro assays.