CD4 and neoplasm: Cox and the Cox product PGE2 in tumor-associated macrophages and tumors, have been reported to decrease the activation and proliferation of T cells (CD4+, CD8+), increase release of IDO1, reduce the function of NK cells, cause a shift from Th1 to Th2 response, increase the infiltration of regulatory cells into the tumor and release of immunosuppressive cytokines, decrease immunostimulatory cytokines, and to drive negative DAMPs (damage-associated molecular patterns) (137–141).