PTGS2 and neoplasm: Considering that current therapies for lung cancer are based in the blockade of PD-L1 to reactivate tumor immunity, we are also speculating that due the continuous PGE2-dependent induction of PD-L1 expression on myeloid suppressor cells, a synergistic therapy focused on blocking Treg and COX2 might be a more powerful approach to reverse immunosuppression in prostate cancer.