PTGS2 and neoplasm: In BC tissue, COX-2 expression is induced by pro-inflammatory cytokines, notably TNFα, and the resultant increased PGE2 levels are associated with large tumor size and high proliferation rates [131,145], due to, in part, the induction of aromatase expression via activation of cAMP-PKA and PKC-mediated signaling cascades [141,146,147].