Prostaglandins have various physiological effects, including activation of inflammatory pathways. They are derived from arachidonic acid, the synthesis of which is believed to be mainly regulated by phospholipase A2. Nomura et al. show that monoacylglycerol lipase (MAGL) mediates an alternative prostaglandin biosynthetic pathway. Moreover, they show that inactivation of MAGL is neuroprotective in Parkinson's disease mice, and that this effect is probably mediated through a decrease in neuroinflammation. Thus, MAGL may be an anti-inflammatory target in neurodegenerative disease therapy.