Nuclear factor-κB (NF-κB) is a family of transcription factors that regulate cellular responses to a variety of stimuli, including stress, ultraviolet radiation, microbial components, growth factors, and cytokines. Assessment of NF-κB activation can be investigated by measuring the expression of NF-κB-responsive genes and their products, typically using polymerase chain reaction (PCR) and/or immunoblotting for protein. Alternatively, translocation of NF-κB subunits from the cytosol to the nucleus can be measured using microscopy techniques. However, these methods can be complex and time-consuming. Luciferase-based reporter systems allow for rapid detection of gene expression. This chapter details the use of myeloid cells stably transfected with NF-κB-inducible luciferase reporter constructs to assess the effects of inflammatory stimuli and MIF inhibitors on NF-κB activation.