PTGS2 and breast cancer: These fibroblasts were prone to aggravate the metastasis of breast cancer through skewing DCs and monocytes to an immunosuppressive phenotype by virtue of the release of the COX-2 mediator prostaglandin E2 (PGE-2), which could be abrogated by the specific blockade of ptgs2 (gene encoding COX-2) in the fibroblasts.