SC75741 (4SC-301; V1810) is a potent NF-kappaB (NF-κB) inhibitor (IC50 = 200 nM against 10 ng/mL TNF-α-induced NF-κB reporter gene expression in A549 cells) that impairs p65 subunit (RelA) DNA-binding activity without affecting p65 phosphorylation or nuclear translocation, nor proteasome-mediated IκBα degradation. SC75741 induces apoptosis in multiple myeloma cultures (IC50 from 5 to 12 µM in 48 hrs; OPM2, U266, NCI-H929, RPMI-8226), but not PBMCs (89% viability post 4-hr 100 µM SC75741 treatment). NF-κB inhibition by SC75741 treatment is reported to effectively block influenza virus propagation both in cultures in vitro (1-5 µM) and in mice in vivo (5 mg/kg daily i.v. or 7.5-15 mg/kg twice a day i.p.).