PTGS2 and Parkinson disease: In postmortem SN from human PD brains, microglia results activated, lymphocytes are infiltrated [2, 6], and in cerebrospinal fluids, there are high levels of pro-inflammatory cytokines such as tumor necrosis factor (TNF), cyclooxygenase-2 (COX-2), interleukin-1beta (IL-1beta), and IL-18 [7, 8].