Urinary 11-dehydro-TXB₂ excretion and number of ECFCs in polycythemia vera patients. (A) Urinary 11-dehydro-TXB₂ excretion in the entire polycythemia vera patient population (n = 37), and divided according to the ongoing treatment [aspirin (ASA) alone, aspirin plus phlebothomy (Phl), or plus hydroxyurea (HU)] as well as in healthy controls (n = 12). ● represents patients with a history of previous thrombotic events. represents the 95th percentile of 11-dehydro-TXB₂ values in the control group. (B) Number of ECFCs in the entire patient population (n = 37), and divided according to the ongoing treatment [aspirin (ASA) alone, aspirin plus phlebothomy (Phl), or plus hydroxyurea (HU)] as well as in healthy controls (n = 12) and in controls after a 8-week treatment with low-dose aspirin (100 mg/od) (n = 6). ● represents patients with previous thrombotic events.