What happened: Former Dallas Cowboys defensive end Marshawn Kneeland has been diagnosed with stage 1 CTE by Boston University researchers. The determination comes following his death by suicide at age 24 in November 2025.

Why it matters: The finding adds to the growing medical data regarding early-onset brain injuries in young athletes. Identifying the condition in a player who passed away during his early twenties underscores the ongoing focus on long-term neurological health.

What to watch: Medical experts will likely incorporate these findings into broader studies on football-related head trauma.