QNZ (EVP4593) is primarily used as a potent and selective inhibitor of the NF-κB signaling pathway, which plays a central role in regulating the immune response, inflammation, and cell survival. Due to its ability to suppress NF-κB activation, QNZ is widely applied in research settings to study inflammatory diseases, viral infections, and cancer. It has been shown to reduce the expression of pro-inflammatory cytokines and mediators, making it a valuable tool in investigating conditions such as sepsis, arthritis, and neuroinflammatory disorders. In oncology research, QNZ is used to explore mechanisms of tumor cell proliferation and apoptosis, as constitutive NF-κB activation is often associated with tumor progression and resistance to therapy. Additionally, it has been employed in virology to study viral replication processes that depend on NF-κB, including HIV and hepatitis B virus. Its application remains limited to laboratory research and is not used clinically.