"The NFL, both directly and in partnership with the NIH, Centers for Disease Control and other leading organizations, is committed to supporting a wide range of independent medical and scientific research that will both address CTE and promote the long-term health and safety of athletes at all levels."
NFL teams have given a $30 million research grant to the NIH.
Before shooting himself, Duerson, a former Chicago Bears defensive back, left a note asking that his brain be studied for signs of trauma. His family filed a wrongful-death suit against the NFL, claiming the league didn't do enough to prevent or treat the concussions that severely damaged his brain.
Easterling played safety for the Falcons in the 1970s. After his career, he suffered from dementia, depression and insomnia, according to his wife, Mary Ann. He committed suicide last April.
Mary Ann Easterling is among the plaintiffs who have sued the NFL.
"It was important to us to get to the bottom of this, the truth," Gina Seau said, "and now that it has been conclusively determined from every expert that he had obviously had it, CTE, we just hope it is taken more seriously.
"You can't deny it exists, and it is hard to deny there is a link between head trauma and CTE. There's such strong evidence correlating head trauma and collisions and CTE."
Tyler Seau played football through high school and for two years in college. He says he has no symptoms of brain trauma.
Gina Seau's son Jake, now a high school junior, played football for two seasons but has switched to lacrosse and has been recruited to play at Duke.
"Lacrosse is really his sport and what he is passionate about," she said. "He is a good football player and probably could continue. But especially now watching what his dad went through, he says, 'Why would I risk lacrosse for football?'
"I didn't have to have a discussion with him after we saw what Junior went through."
Her 12-year-old son, Hunter, has shown no interest in playing football.
"That's fine with me," she said.