GSTM1 and myeloproliferative neoplasm: miR methylation was not associated with age (p = 0.651), gender (p = 0.225), MPN subtype (p = 0.484), presenting Hb (p = 0.874), presenting leukocyte count (p = 0.969), presenting platelet count (p = 0.328), myeloid transformation (p = 0.99), thrombotic events (p = 0.311) or JAK2 V617F mutation (p = 0.99).