Transmembrane signalling systems are an integrated series of pathways, leading to various effects depending on cell type. A simplified picture is of a ligand activating a cell surface receptor, initiating a series of events inside the cell which, in turn, leads to gene expression. The real story is rather more complex and researchers investigating different areas of signal transduction gathered together to discuss and present topics of potential therapeutic relevance at the recent IBC UK conference on Signal Transduction - Targets for Therapeutic Intervention [London, UK; November 1997]. Although based at a fundamental biological research level, the conference did raise issues which will need to be addressed by any pharmaceutical company wishing to develop a drug targeting this area.