SERPINE1 and post-traumatic stress disorder: Indeed, compared to vehicle-injected mice (n = 15), PAI-1-injected mice (n = 14) displayed PTSD-like fear memory with an abnormally high fear response to the salient, but irrelevant, tone (Fig. 4a, c—treatment × block during the tone test: F2,54 = 20.709; p < 0.0001; treatment effect in tone ratio: p < 0.0001), and a decreased fear response to the predictive context (Fig. 4b, d—treatment effect (three blocks) during the context test: F1,54 = 5.006; p = 0.0337), which was mainly observed during the first 2-min block (p = 0.0202).