Overall outcomes for Epo-dependent Ter119-positive cell formation from EpoR-HM versus wt-EpoR EPCs. Graphed are the frequencies of Ter119-positive cells formed in the presence of Epo at 0.1, 0.4, and 1.6 U/mL for marrow preparations from 10 EpoR-HM and 10 wt-EpoR mice. Differences between means (horizontal bars) were tested for significance (P values) using Student t distribution.