On the cover: Gill preparation dissected from an adult zebrafish carrying the cd4-1:mCherry reporter transgene. CD4⁺ cells (red fluorescence) can be seen resident in the epithelium of the branchial filaments and lamellae epithelium. Dee, C. T., R. T. Nagaraju, E. I. Athanasiadis, C. Gray, L. Fernandez del Ama, S. A. Johnston, C. J. Secombes, A. Cvejic, and A. F. L. Hurlstone. 2016. CD4-transgenic zebrafish reveal tissue-resident Th2- and regulatory T cell–like populations and diverse mononuclear phagocytes. J. Immunol. 197: 3520–3530.