Subsequently, Allen et al. [115] utilised a panel of established human cancer cell lines to show that IR-induced, caspase-3-dependent, PGE2 production is a common response of irradiated tumour cells and that PGE2 production generally correlated with enhanced growth of cells that survive irradiation and of unirradiated cells cocultured with irradiated cells. Here, CASP3 is linked to cancer.