Boston University School of Medicine researchers found more than 90 percent of deceased NFL players' brains they studied had chronic traumatic encephalopathy, according to NBC Sports.
Here are three key points:
1. The researchers pointed out their sample size is not complete, as they only looked at brains of authorizing players.
2. Although the study demonstrates a connection between football and CTE, the researchers concluded they do not know how many NFL players develop CTE.
3. A study needs to analyze NFL players' brains against non-NFL players' brains to establish a CTE trend among NFL players.