title: Forewarned is forearmed.
abstract: Memory killer T cells contribute to control of secondary viral infection by exhibiting rapid effector function upon reinfection. In this issue of Immunity, Kohlmeier et al. (2010) demonstrate that type I interferon is key for rapid upregulation of effector function within circulating memory T cells, ensuring efficient control of infection.
authors.affiliation: Department of Microbiology and Immunology, The University of Melbourne, Royal Parade, Parkville, Victoria, 3010, Australia.
authors.forename: Nicole
authors.initials: N
authors.lastname: La Gruta
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Turner