(a) NK cells were sorted by flow cytometry (NK1.1+NKp46+CD3-CD49b+) from wildtype C57Bl/6, Pkm2fl/fl or Ncr1CrePkm2fl/fl mice. Cells were lysed and DNA was purified. DNA was subject to PCR amplification for the Pkm2 gene and products were electrophoresed on a 1.8% agarose gel and imaged. (b) Splenic Pkm2NK-WT and PKM2NK-KO NK cells were analysed by flow cytometry for the expression of CD11b and CD27. (c) Pkm2NK-WT and Pkm2NK-KO cells were isolated and counted and analysed by flow cytometry for frequency of NK1.1+NKp46+CD3- cells. (d) Splenic Pkm2NK-WT and Pkm2NK-WT cells were expanded for 6 days in IL-15 (15 ng/mL). Data displayed show total splenocyte numbers before expansion (pre) and pure NK cell numbers after magnetic purification (pure). (e–h) Pkm2WT and Pkm2KO NK cells were stimulated for 18 hr in IL-2/12 or left unstimulated. NK1.1+NKp46+CD3- cells were analysed for granzyme B (e–f) or IFNγ expression (g–h). (i–j) Pkm2NK-WT and Pkm2NK-KO cells were stimulated for 18 hr in IL-2/12 or left unstimulated and media supernatants were collected. Supernatants were then analysed for by cytometric bead array analysis for (i) IFNγ, IL-10, TNF, (j) MIP1α, MIP1β. (b–j) data are mean +/- S.E.M for n = 4–8 mice per group. (c) Data was analysed using a Students t test. (b, d-i) Data were analysed by two-way ANOVA with multiple comparisons. *p>0.05, **p>0.01, ***p>0.001.