Therefore, the caspase-3/PGE2 axis is a direct link between cell death and tumour repopulation, highlighting that tumours may exploit a tissue homeostatic mechanism to preserve themselves when damaged by cytotoxic therapy, and given the high radiation doses required to kill high numbers of tumour cells, the rare surviving cells are likely to experience significant DNA damage, and rapid proliferation of such cells may enhance mutagenesis and drive tumour progression toward a more metastatic state. Here, CASP3 is linked to neoplasm.