S100A9 and viral infectious disease: Genes involved in the response to microbial products include receptors known to sense gonococci (TLR2, NOD2, NLRP3), antimicrobial peptides (DEFB4A and S100A9), and several interferon-induced genes typically associated with viral infection and intracellular bacteria (multiple OAS, GBP, and IFI type genes)43–45.