(D) Granzyme release. YTS KIR2DL1 cells were mock-transfected or transfected with N.S siRNA or SHP-1 and Cbls siRNA. After 48 hours, cells were incubated with either 721.221 Cw4 or Cw7 target cells, the supernatant was then collected and granzyme B levels were evaluated using ELISA sandwich assay. The levels of granzyme B were quantified using standard recombinant granzyme B concentrations Data are means ± SEM of eight independent experiments;(n=8); P values were calculated by One way ANOVA following Tukey's post hoc analysis, and are indicated by asterisks *P < 0.05.. 