Scientists say they have finally been able to detect evidence of chronic traumatic encephalopathy—or CTE—in a living patient. A new study, undertaken by lead author and pathologist Bennet Omalu, suggests that experts can diagnose the disease while a patient is still alive by detecting the presence and deposits of tau proteins—instead of requiring an autopsy for formal diagnosis. Omalu told CNN that the unnamed player in the study is actually Fred McNeill, who played for the NFL’s Minnesota Vikings and died in 2015. Omalu—whose work the 2015 film Concussion was based on—said he initially diagnosed McNeill in 2012 using a brain scan that traced tau, a signature protein of CTE. They later confirmed that diagnosis with an autopsy, after McNeill passed away. Omalu’s case study was published in Neurosurgery this week.