The cast and crew of Concussion, as well as the film's subject Dr. Bennet Omalu, celebrated the AFI Fest world premiere of the drama at the TCL Chinese Theatre Tuesday night. Concussion, which is based on a true story, centers on Will Smith's Omalu, an immigrant pathologist who discovers a football-related brain disease called CTE while investigating the unexpected death of former Pittsburgh Steelers center Mike Webster. In preparation for the role, Smith spent months and months researching with Omalu, specifically watching him and other pathologists perform autopsies. At the premiere, the actor noted he gained a deeper understanding of Omalu's mission to reveal the truth behind long-term brain damage in football players.