SC75741 is a broad and efficient NF-κB inhibitor with an IC50 of 200 nM for p65. SC75741 blocks influenza viruses (IV) replication. SC75741 impairs DNA binding of the NF-κB subunit p65, resulting in reduced expression of cytokines, chemokines, and pro-apoptotic factors. SC75741 subsequently inhibits caspase activation and blocks caspase-mediated nuclear export of viral ribonucleoproteins.