Pattern of activating receptors expression on CD3^-CD56⁺NK cells after haploidentical SCT. (A, left) Frequency of CD3^-CD56⁺ NK cells expressing NCRs NKp30, NKp44, or NKp46, in 2 donor-recipient pairs (no. 10, no. 9). Cells were stained at the time of engraftment (day 15) and in the months thereafter. Results are expressed as the percentage of CD3^-CD56⁺ cells positive for NKp30 (▪), NKp44 (▦), or NKp46 (□). (Right) Representative histogram analysis of each NCR for 1 patient (no. 10) at 90 days after graft, compared with the donor. (B, top) NKp44 is expressed mostly on CD3^-CD56^bright NK cells. Percentage of CD3^-CD56^dim (▪) or CD3^-CD56^bright NK cells (□) expressing NKp44 in the total population of CD3^-D56^dim or CD3^-CD56^bright NK cells are represented at different times after SCT and compared with the donor. M indicates month. (Bottom) FACS distribution of NKp44⁺ NK cells in CD3^-CD56^dim and CD3^-CD56^bright subpopulations is indicated for patient no. 10 at day 90. Values shown are percentage of NK cells (gated by CD3^-CD56⁺) that expressed NKp44 in the various quadrants.