Researchers find a substance called tau in the blood of living former NFL players . Its pattern is identical to that found in chronic traumatic encephalopathy patients . It can only be detected after death . More research is needed to confirm the findings .
Researchers find a protein called tau in the brains of living retired NFL players . Its pattern is identical to that found in chronic traumatic encephalopathy cases . CTE can only be diagnosed after death . More study is needed to confirm the findings .