When PEGs were present during the 90-min infection step, it had no effect on cellular integrity as measured by LDH release, while the addition of PEGs during the post-infection 3 h period clearly prevented leakage of cytosolic contents (Supplementary Figure S2B), suggesting that most cell death occurs during the later phase of the experiment and subsequent to IL-1β release. This evidence concerns the gene IL1B and infection.