Indeed, it has been shown in AD human brain homogenates that plasmin activity is reduced as compared to that of normal subjects.37 In addition, brain tissue (hippocampus and neocortex) homogenates from AD patients have reduced plasmin levels.38 Nonetheless, in other studies, it was shown that plasminogen and plasmin protein levels were not significantly altered in frontal and temporal cortex homogenates from AD patients.35 Here, PLG is linked to Alzheimer disease.