Chronic traumatic encephalopathy is the neurodegenerative disease that is ascribed to the long term development of cognitive, behavioral, emotional, and motor deficits as a result of the exposure to high amounts of sub concussive traumatic brain injuries. The disease has gained recent popularity in the media for its prevalence in American football as a response to recent research that has suggested the prominence of the disease in nearly every NFL player that is examined post mortem. This has produced a growing concern for the consequences of head impact and participation in contact sports. Despite media attention, little is currently known about the specific causes of the disease and an in life diagnosis is still nonexistent. The present study proposes that the chemokine, CCL11, could prove to be a viable biomarker for recognizing the onset and progression of chronic traumatic encephalopathy. The results of our study suggest that football players who are clinically suspicious of CTE show significantly higher levels of CCL11 in their cerebrospinal fluid than do sedentary controls and noncontact athletes. Our results demonstrate that this increase in CCL11 is correlated with the number of years that a football player had participated in. We also suggest that this increase in CCL11 is associated with a unique immune response through results showing that the CCL11 expression increase is correlated with an increase in the expression of the cytokine IL-4 and substantial decrease in IFN-gamma. The analysis of CCL11 expression levels in the cerebrospinal fluid may prove to be a viable method of diagnosing and providing treatment for patients who may be at risk of chronic traumatic encephalopathy.