PTGS2 and breast neoplasm: Because Cox-2 is involved in the production of bioactive lipid PGE2, and we previously identified PGE2 as a downstream effector of caspase-3 in tissue regeneration [21], angiogenesis [11], and breast tumor repopulation [10], we hypothesized that caspase-3 could promote PGE2 production by increasing Cox-2 expression in dying NSCLC cells.