NKG2A⁺ NK cells predominate functional responses early after T cell–replete and T cell–depleted SCT. Gates were set on CD107a⁺ NK cells and the relative contribution of the indicated NK-cell subset to the total degranulation response was assessed in the donor before SCT and in the recipient at the indicated time points after SCT in T cell–replete (left panel) and T cell–depleted (right panel) settings. Shown are mean values of 6 (T cell–replete) and 5 (T cell–depleted) donor-recipient pairs. Error bars represent SEM.