Blimp hovers over T cell immunity.

The functions of T lymphocytes are regulated by transcription factors controlling gene expression. Three studies in this issue of Immunity (Kallies et al., 2009; Rutishauser et al., 2009; Shin et al., 2009) indicate that the transcriptional repressor Blimp-1 promotes the development of short-lived effector cells and regulates clonal exhaustion.