IRS⁺ T-cell clones produce a high amount of IFN-γ and TNF-α. T-cell clones expressing IRS activating isoforms (CD3⁺KIR⁺CLIR⁺ clones: C3.50 [KIR2DS2⁺, from PNH5], ▪; and A1.25 [KIR2DS1⁺, from PNH6], □) were stained with either anti-CD3, anti-KIR, anti-CLIR, or anti-CD54 (isotype-matched control mAb) mAbs and incubated in plates precoated with goat antimouse antiserum. After 24 hours, culture supernatants were harvested and analyzed by ELISA for the presence of either IFN-γ (A) or TNF-α (B). “None” represents the release of either IFN-γ or TNF-α in the absence of any mAb. Results are expressed as mean of triplicate samples; bars indicate standard deviation of triplicate samples.