Deficient Ca²⁺mobilization by RMA-H60-exposed NK cells. NK cells were loaded with Indo-1 before incubating with either anti-NKG2D antiserum or anti-Ly49D (4E5) mAb. Residual B and T cells were excluded by gating on CD19^- and CD3^- cells. The data acquisition was interrupted for cross-linking the bound mAb with goat anti-rat IgG. The results shown are from one experiment of 2 performed.