Influence of androgen on telomerase activity of hematopoietic stem and progenitor cells. CD34⁺ cells were separated on immunomagnetic columns and cultured in long-term liquid media in the presence of methyltrienolone (R1881) for 8 days (n = 3), when they were harvested for flow and cell-cycle analyses and protein extraction. No changes in CD71 (transferrin receptor, erythroid marker) or CD33 (myelomonocytic marker) expression patterns were observed upon male steroid treatment.