PTGS2 and Parkinson disease: Our results provide strong support for the hypothesis that an exacerbated inflammatory process, potentially as a result of COX-2 mediated microglial activation, is detrimental to dopaminergic neurons; and that inhibition of COX-2 prevents progression of PD-like pathology and symptoms by breaking a vicious circle of perpetual microglial activation, thus producing the neuroprotective properties we observe.