BioEssays

ABSTRACT Once considered biochemical oddities, dinucleoside polyphosphates such as diadenosine tetraphosphate (Ap4A) are now recognized as conserved signaling molecules involved in essential cellular processes, including stress response, RNA stability, and proteostasis. To capture recent advances and reignite collaborative efforts in this re-emerging field, the one-day symposium ?Dinucleoside Polyphosphates in Cellular Signalling: Function and Evolution Across Life? was held in Marburg on May 27, 2025. The meeting brought together researchers across disciplines and domains of life to share insights into Ap4A's diverse roles?from bacterial virulence and plant signaling to human disease?and showcased powerful new tools for studying its function, laying the groundwork for future discovery and innovation.