Ly49 and CD94/NKG2 receptor expression on NK cells following administration of neutralizing LTβR-Ig. B6 mice were injected once a week during 5 weeks with 100 μg LTβR-Ig or control human Ig (chuman Ig). One week after the last injection, flow cytometric analysis was performed on splenic NK cells enriched by negative selection using anti-CD4, anti-CD8, and anti-IgG beads. Cells were incubated with a combination of mAbs for NK1.1, CD3, and the indicated Ly49 receptors or CD94/NKG2. Data were collected from gated NK1.1⁺CD3^– NK cells and are presented as the mean ± SD. *Statistically significant differences (by Student t test) between LTβR-Ig (n = 3) and chuman Ig (n = 5) treated mice. Results from B6 control stainings (n = 8) are also shown.