In the context of ischemic stroke, peripheral blood-derived exosomes containing hyaluronan-binding protein 2 (HABP2) promote the expression of protease-activated receptors 1 (PAR1) in astrocytes causing activation of the phosphoinositide 3-kinase (PI3K) / AKT / mTOR pathway (Fig. 1) [60]. Here, AKT1 is linked to ischemic stroke.