p53 and p73: seeing double?

Whereas p73 is closely related to the tumour-suppressor protein p53, its contribution to tumour suppression and the spatial and temporal regulation of its isoforms is unclear. It has now been established that p73 is a transcriptional target of E2F1. Its ability to induce apoptosis in TP53(-/-) cells indicates a tumour-control mechanism that runs parallel to but independent of that mediated by p53. The new results illustrate a complex cross-talk between p53, E2F1 and p73