MAPT and brain injury: Review of the clinical trial database on ClinicalTrials.gov shows 21 studies currently listed evaluating “tau + PET” for “traumatic brain injury.” Of the 21 listed studies, 10 have been completed, 4 of which have results, 1 is active, not recruiting, 2 are enrolling by invitation, 2 are recruiting, 1 is not yet recruiting, 1 has been terminated, 3 have been withdrawn, and 1 has a status unknown.