What happened: Former Cowboys DE Marshawn Kneeland, who died by suicide, has been diagnosed with chronic traumatic encephalopathy (CTE). Posthumous testing formally established the presence of the degenerative brain disease.

Why it matters: The diagnosis provides a tragic data point in the ongoing scrutiny over head trauma and long-term player safety in professional football. It also underscores the severe neurological toll associated with repetitive impacts.

What to watch: Advocates will likely point to this case when pushing for advanced research and enhanced preventative measures across the sport.