The most plausible explanation is that the enhanced cell survival conferred by DRAK2 silencing (by COX-2) provide a resistance to various forms of cell death and possibly crucially to anoikis (matrix detachment-induced cell death) (Hofmann et al, 2007), the form of cell death that may be the most important in deciding the viability of circulating tumour cells and their ability to form distant metastases. This evidence concerns the gene PTGS2 and neoplasm.