Overall outcomes for annexin V analyses of Ter119-positive EPCs from EpoR-HM versus wt-EpoR mice. Summarized are direct frequencies of annexin V–stained Ter119-positive EPCs formed in the presence of Epo at the indicated doses (0.1, 0.4, 1.6 U/mL) (events scored are percent annexin V–positive cells among Ter119-positive cells). Data points are frequencies for individual mice (and are derived from 2 representative but independent experiments). Horizontal lines represent mean values.