JAK2 and myelofibrosis: Only 4 years after the disease beginning a diagnosis of chronic MPN (primary myelofibrosis) was established according to WHO criteria: multilineage hyperplasia with megacaryocyte dysplasia and myelofibrosis in the bone marrow histology, palpable splenomegaly, increased serum LDH, anemia, detection of the JAK2 V617F positive mutation in absence of cytogenetic abnormalities, the hyperhomocysteinaemia was confirmed and considered an additional risk factor of thrombosis.