Studies have reported elevated plasma t-tau and p-tau, as well as a ratio of p-tau over tau in severe TBI patients 6–8 months after injury.166 T-tau in blood samples collected 1 h after sports-related concussion showed diagnostic accuracy for TBI.167 A recent study found that levels of tau, ß-amyloid-42, and IL-10 were higher in exosomes of military personnel who had experienced mTBIs than in personnel who had not.168 Among TBI patients, regression models show that post-concussive symptoms are most related to exosomal tau elevations, whereas exosomal IL-10 levels relate to PTSD symptoms. Here, MAPT is linked to brain injury.