TSPO and psychiatric disorder: Stages of disease progression for CTE represent another variable as neuroinflammatory responses are not uniform, and is consistent with chronic neurodegenerative disease and psychiatric disorders.60 The varying cell-type expression of TSPO in CTE demonstrated herein by immunostaining suggests that the contribution of microglia, astrocytes and peripheral infiltrated macrophages all need to be considered when assessing neuroinflammation in CTE with TSPO-PET radiotracers.