A. mCherry-OCEL, but not mCherry-OCELK433D, prevented TNF-induced acceleration of EGFP-occludin fluorescence recovery. B. mCherry-OCEL, but not mCherry-OCELK433D, blocked TNF-induced EGFP-occludin (green) endocytosis (arrows). Cells expressing mCherry-OCEL or mCherry-OCELK433D, can be identified by their red fluorescence. Adjacent cells not expressing mCherry-OCEL or mCherry-OCELK433D, all show TNF-induced EGFP-occludin internalization. From Buschmann et al. Mol Biol Cell. 2013.