SERPINE1 and Alzheimer disease: Accordingly, the tPA–plasmin axis has been implicated in several neuronal activities, including LTP,29 LTD,30 NMDA receptor‐mediated signaling,31 and synaptic remodeling.32 These data suggest that tPA and its inhibitor PAI‐1 may play a role in synaptic modulation in normal as well as in pathological conditions, such as those occurring during the course of AD.