PRF1 and Sepsis: In addition, these results are strengthened by a significantly lower cytotoxic module score (calculated using the AddModuleScore function in Seurat V4 using the cytotoxic-related genes GZMH, GZMK, GZMA, GZMB, PRF1, and GNLY) in all sepsis cytotoxic cell subsets compared to bacteraemia and controls (Figure 8A).