COX-2-derived PGE2 has been shown to mediate the crosstalk between colonic tumor cells and macrophages [74], induce the accumulation and activation of myeloid-derived suppressor cells [68,69], and promote the tumor growth of mutant BrafV600E mouse melanoma cells by suppressing immunity and fueling tumor-promoting inflammation. The gene discussed is PTGS2; the disease is neoplasm.