Scientists have recently demonstrated that cathepsin B, a well-studied protein important to brain development and function, can be used as biomarker, or indicator of severity, for TBI. TBI trauma results from blows to the head, leading to life-changing disruption of the brain and a cascade of long-term health conditions. Biomarkers are a source of great interest to researchers due to their potential to dramatically improve both the diagnosis and categorization of severity of TBI.