Increased frequency of Ly49G2^high NK cells in IL-2–treated mice. B6 (H-2^b) and B10.D2 (H-2^d) mice received recombinant human IL-2. Gated splenic CD45⁺NK1.1⁺CD3⁻ cells expressing Ly49s in IL-2–treated mice versus untreated mice are shown. (A) Frequencies of NK cells positive for Ly49G2 in B6 and B10.D2 mice. (B) Intensity levels of Ly49G2 expression as determined by MFI on control (tinted gray) and treated (solid dark lines) mice. Distribution of NK-cell subsets in B6 (C) and B10.D2 (D) mice. *P < .01; **P < .001. NS indicates not significant. The numbers represent the percentages of cells or MFI values. Data are representative of 3 experiments using 3-4 mice per group in each experiment (means ± SEM).