Cross-signaling schematic. Signaling pathways activated by viral by-products and involving potential targets for IRF3, NF-κB and SP1 (including their main target, IFNβ). Green arrows: confirmed positive regulation. Red lines with bullet endings: confirmed negative regulation. Blue dashed arrows: Co-regulation of unknown type inferred from bioinformatics and evolutionary analysis. Bold lines: Strong association of TF based on high counts of binding sites in target gene promoters.