CD34 and acquired polycythemia vera: Analyses were extended to primary erythroleukemias (AML M6) and polycythemia vera patient samples, documenting high expression of VENTX in clear contrast to PML-RARα positive AML, which did not show any detectable expression of VENTX as well as in contrast to CD34+ progenitor cells from normal bone marrow (Figure 2B, Table 1).