ITGA2B and acquired polycythemia vera: The median output of CD41+ megakaryocytes at day 14 was 2.2% (range: 1.02–3.37) in CTRL, 8.61% in pre-fibrotic PMF (range: 3.6–30.86), 8.51% in fibrotic PMF (range: 2.33–56.71), 8.18% in ET (range: 1.7–19.8), 7.36% in PV (range: 2.8–24.9).