While the overall frequencies of natural killer cells (NK) were not changed in blood or BAL (Supplementary Fig. 2b, e), the fraction and absolute number of Granzyme B + NK cells increased significantly at 2 dpi in blood, from 4 to 25% (Fig. 1e) and remained elevated throughout the course of infection (Supplementary Fig. 2b, e). This evidence concerns the gene GZMB and infection.