PTGS2 and neoplasm: Moreover, secretion of TGF-β, IL-10, chemokine (CC motif) ligand 22 (CCL22), cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) and chemokine (C-C motif) ligand 2 (CCL2) will recruit immune regulatory cells such as regulatory T cells (Tregs) and myeloid derived suppressor cells (MDSCs) into tumor lesions [10-12].