Three days after infection with aSFV the percentage of gzmA expressing NK cells had not changed significantly (data not shown) whereas a large (>60%), similar proportion of NK cells in gzm-sufficient animals were activated, as assessed by intracellular gzmB protein expression of NK cells in spleens (Fig. 1D) and popliteal lymph nodes (data not shown). This evidence concerns the gene GZMA and infection.