Human dimeric erythropoietin stimulates late erythroid progenitors.

CD36⁺ cells were purified and grown in semisolid medium containing 0.1 to 0.4 U/mL (as determined by proliferation assay) hEpoM (black) or hEpoD (white). Experiments were performed in triplicate. Mean CFU-e numbers (A) and mean erythroid cell number (B) were measured 7 days later.