The insulin/IGF-1 signalling (IIS) pathway is involved in various biological processes, including regulation of longevity. In the worm Caenorhabditis elegans, the transcription factor DAF-16a, one of two isoforms, has a major role in this pathway, regulating longevity, stress response and dauer diapause. These authors describe a new isoform, DAF-16d/f, which is also important in the regulation of lifespan. The DAF-16 isoforms functionally cooperate to fine-tune IIS-mediated processes in the context of a whole organism.