Bill Gray (American football coach)
Bill Gray is a former American football and tennis coach.
He served as the full- time head football coach at Samford University from 2002 to 2006, after being named the interim head coach midway through the 2001 season.
Gray is a 1991 graduate of Mississippi College, where was the head tennis coach in the early 1990s.
Doyle Royal
Doyle P. Royal( born January 29, 1919) is an American collegiate soccer and tennis coach.
He coached the University of Maryland soccer team from 1946 to 1973, and the tennis team from 1954 to 1980.
Balls Out: Gary the Tennis Coach
Balls Out:
Gary
the Tennis Coach is a 2009 American sports comedy film directed by Danny Leiner (his final film before his death in 2018) and features actor Seann William Scott as the main character and Randy Quaid in a supporting role.
It was filmed mostly in Austin and Taylor, Texas, and was released direct-to-video on January 13, 2009.
John Roddick
John Roddick( born July 4, 1976) is an American former professional tennis player and the current director of tennis and head men's tennis coach at the University of Central Florida.
Ian Barry (director)
Ian Barry is an Australian director of film and TV.
Peter Levin
Peter Levin is an American director of film, television and theatre.
Vladimir Obradović
Vladimir Obradović( born 4 February 1981) is a Serbian tennis coach and former professional tennis player.
Dušan Vemić
Dušan Vemić is a Serbian tennis coach and former professional tennis player.
Jerry Simmons (tennis)
Jerry Simmons is an American tennis coach, known as" Coach Simmons."
Danny Leiner
Daniel Leiner (May 13, 1961 – October 18, 2018) was an American film director.
His credits include "Dude,
Where's My Car?"
and "Harold & Kumar Go to White Castle".
He was born in Manhattan, New York in 1961.
Leiner also directed a wide range of television including "Arrested DevelopmentEverwoodGilmore GirlsFreaks and GeeksSports NightFelicityActionThe Tick", MTV's "Austin Stories" and HBO's "The Mind of the Married ManThe Sopranos" and "How to Make It in America".
He also directed an episode of "The Office" entitled "WUPHF.com".
Leiner died from lung cancer on October 18, 2018, at the age of 57.

Question: What is the cause of death of director of film Balls Out: Gary The Tennis Coach?
Answer: lung cancer