CD34 and myelofibrosis: Taking into account that the constitutive mobilization of CD34+ cells into the peripheral blood in myelofibrosis has been suggested to be due to action of a number of proteases [25] and the JAK2V617F mutation may be deeply involved in this process as well by constitutively activating granulocytes and by this means mobilizing CD34(+) cells [28] our findings are certainly supportive.