Immunostaining of the neuronal marker beta III tubulin (green) and the transcription factor nuclear factor kappa B p65 (NF-κB, also known as RelA, red) in the LUHMES human neuronal cell line at differentiation day 2 (upper panels) and day 6 (lower panels). Nuclei are stained with Hoechst (blue). Inactive NF-κB is held in the cytoplasm by its inhibitor, IκB (left panels). Upon activation, IκB is phosphorylated by IκB kinase (IKK), and NF-κB is able to translocate into the nucleus, resulting in a pink color in LUHMES cells exposed to a mixture of inflammatory cytokines (middle panels). Pretreatment with the IKK inhibitor TPCA-1 largely prevents NF-κB nuclear translocation following cytokine exposure (right panels). For more information see the article by Prof. Pamela Lein et al. on pages 875-887.