Contents

07 August 2007
Vol 2007, Issue 398

About The Cover

Cover image expansion

COVER This week's Focus Issue, published to complement the Science Special Issue on Challenges in Immunology, contains an Editorial Guide, a Review, and two Perspectives that discuss signals that affect the fate and responsiveness of T lymphocytes. The image depicts the activation of a naïve CD4+ T lymphocyte by a dendritic cell and its subsequent expansion and differentiation into a long-lived memory cell. [Image: Preston Huey, AAAS]