Impaired expression and function of NKp46 on freshly isolated NK cells. (A) NKp46 expression on freshly isolated bulk NK cells. Staining was detected by mAb 461-G1 in the form of F(ab′)₂, and the MFI staining is indicated in each histogram. One representative experiment is shown of 3 performed. (B) Killing of .221 cells by freshly isolated NK cells derived from indicated donors. The mean results of 3 independent experiments are shown. The data represent means of the percentage of killing ± SDs.