title: Editorial: memory CD8 T cells now join "Club 21".
abstract: In this volume, Nguyen and Weng [( 1) ] show an intriguing study in which they observed an antagonizing effect by IL-21 on the IL-7- or IL-15-driven expansion of CD28(-) nonfunctional memory CD8 T cells and thereby, proposed a new role for IL-21 to keep the memory pool fresh and competent. I will summarize previous studies and discuss the recent advancement in this context.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tagaya
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D006801:Humans; D007156:Immunologic Memory; D007378:Interleukins / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D050796:STAT3 Transcription Factor / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D057170:Translational Research, Biomedical; D053632:X-Linked Combined Immunodeficiency Diseases / Q000503:physiopathology; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D050796:STAT3 Transcription Factor; D000098546:Interleukin-21