Expanding NKG2C^-NKG2A^- NK cells express activating KIRs. (A) Expansions in the NKG2C^-NKG2A^- compartment with a differentiated phenotype are marked with red circles. False-positive outliers with less differentiated phenotypes are marked with small blue circles. Gray dots represent the KIR repertoires in the 199 donors. (B) KIR expression patterns in representative CMV-seropositive donors with KIR2DS4⁺ expansion in the NKG2A^-NKG2C^- NK cell subset. (C) Identification of NK cell expansions in CMV-seropositive donors expressing KIR2DS2 using combinations of the indicated anti-KIR antibodies. Expansions (right) and their respective GL183⁺ internal controls (middle) were gated out, as depicted in the bivariate plots (left). (D) Representative CMV-seropositive donors with NKG2A^-NKG2C^- expansions expressing KIR3DS1. KIR3DS1-single positive cells are shown (Z27⁺DX9^-) after exclusion of KIR3DL1⁺ (Z27⁺DX9⁺) cells.