CD34 and myeloproliferative disorder: Koopmans S.et al. in a study conducted on 106 MPN patients found that increased MVD and development of marrow fibrosis correlated with worse prognosis.23 Ponzoni M.et al. studied MVD using CD105 and CD34 in 55 MPN patients and observed that MVD was associated with poor prognosis, especially in PMF.24 Pizzi M.et al. and Lundberg L.et al. also stated the above in their study.5,25 The above-mentioned study results were concordant with our study.