Tolerance of uneducated NK cells in both T cell–replete and T cell–depleted SCT. CD107a expression by NKG2A−CD56dim NK cells expressing self or nonself KIRs relative to the response of NKG2A−KIR− cells in the donor before SCT and in the recipient at the indicated time points after SCT. Shown are mean values of 6 (T cell–replete) and 5 (T cell–depleted) donor-recipient pairs. Error bars represent SEM.