NOS2 and non-small cell lung carcinoma: Caco-2 cells, however, responded to IL-4 stimulation with downregulation of NOS2 and COX2 and MCP1 encoding genes, PTGS2 and CCL2. Likewise, IL-4 downregulated the expression of PTGS2 in another epithelial cancer, that is, non-small cell lung cancer cells [51].