On the cover: A20 (green), mucin2 (red) and nuclei (blue) in mouse ileum. Note localization of A20 at the luminal interface of the villi. In addition to its specific activity, the A20 Ab reacts nonspecifically with the mucus in goblet cell cups, which appear yellow/orange on the merged image. Wang, J., Y. Ouyang, Y. Guner, H. R. Ford, and A. V. Grishin. 2009. Ubiquitin-editing enzyme A20 promotes tolerance to LPS in enterocytes. J. Immunol. 183: 1384–1392.