The aim of our study was to evaluate the possible effect of lipocalin 2 on thrombotic events in polycythemia vera and essential thrombocythemia patients. The samples of 89 patients were collected and RNA based method was used to evaluate the relative gene expression level of lipocalin 2. 74 samples were available for evaluation. Drawing a cut off point at level 30 relative expression rate, 13 patients with elevated lipocalin 2 expression had thrombotic events during the course of their disease. Based on these data high lipocalin 2 expression level seems to have strong positive predictive value on thrombotic events in patients with polycythemia vera and essential thrombocythemia. Lipocalin 2 may be useful in thrombotic risk stratification in these patients. (C) 2016 Elsevier Ltd. All rights reserved.