Sera from 3 of the 10 SLE patients with KIR reactivity to >3 KIRs blocked the binding of the anti-KIR2DL1/2DS1 mAb EB6B (SLE3, SLE138, and SLE206; Figures 2A,B). The gene discussed is KIR2DL1; the disease is systemic lupus erythematosus.