Purified Ly49A⁺/G⁺ NK subsets are significantly inhibited by the expression of H2-D^d on the target cells. The effect of inhibitory Ly49A/G receptors on NK cell-mediated cytotoxicity of ST63, ST72, and ST77 targets was tested using sorted subsets of Ly49A⁺/G⁺ (○) and Ly49A^-/G^- (•) NK cells. Data are presented as described in the legend to Figure 1B and are representative of 3 independent experiments.