The tumour necrosis factor receptor family: life or death choices

The past twelve months have seen a renewal of interest in the therapeutic p otential of members of the tumour necrosis factor receptor family and their cytokine ligands. This biomedical interest has spawned a number of structu ral studies, which have significantly deepened our understanding of the mol ecular basis for the function of these cell-surface signalling systems. The fresh data have revealed unexpected mechanisms conferring ligand-receptor specificity and have highlighted the structural requirements for the initia tion of intracellular signalling.