Samples were acquired with a calibrated number of Trucount with fluorescent beads Tubes in order to calculate the absolute count of annexin V–PE plus 7-AAD–negative cells among resting (CD25^–) and alloreactive (CD25⁺) T cells. The numbers specified in the figures represent the number of beads in each test and the number of events in the annexin V–PE plus 7-AAD–negative region.