PROS1 and acquired polycythemia vera: Hematological diagnoses encompassed polycythemia vera (n = 3), factor V Leiden mutation (n = 5), methylenetetrahydrofolate reductase (MTHFR) gene mutation (n = 2), activated protein C resistance, protein S deficiency, elevated factor VIII and factor VII levels, beta-2 glycoprotein I antibody positivity, and von Willebrand factor deficiency.