Billy Crystal through the years

Comedian Billy Crystal performs during the Hillary Victory Fund: Stronger Together concert at the St. James Theatre in Manhattan on Oct. 17, 2016.

Billy Crystal attends the grand opening of the Robin Williams Center on Oct. 5, 2016.

Billy Crystal blows a kiss after delivering a eulogy during the Muhammad Ali funeral service at the KFC Yum! Center in Louisville, Kentucky, on June 10, 2016.

Sen. Charles Schumer, left, and Billy Crystal seen in Long Beach on Sept. 15, 2014, where they asked for $2.5 million in government aid to replace 2,500 trees killed by superstorm Sandy.

Billy Crystal films a commercial in his hometown of Long Beach.

The cover of Billy Crystal's memoir, "Still Foolin' 'Em: Where I've Been, Where I'm Going, and Where the Hell Are My Keys?"

Billy Crystal during the time he got to play with the New York Yankees in 2008.

Billy Crystal attends the Tisch School of the Arts annual gala benefit at the St. James Theatre on Dec. 4, 2006.

Billy Crystal poses with a copy of his book "700 Sundays" at a book signing at Dutton's Beverly Hills on Nov. 4, 2005.

Billy Crystal starred in his autobiographical 2004 Broadway show "700 Sundays."

Writer Alan Zweibel, Billy Crystal and director Des McAnuff pose for photos before answering questions from the media during the opening night of "700 Sundays" after-party at Tavern on the Green on Dec. 5, 2004.

Martin Short and Billy Crystal pose after the premiere of "A Mighty Wind" at the Directors Guild on April 14, 2003, in Los Angeles.

Lily Tartikoff, Billy Crystal and Debra Messing arrive at the Revlon Run/Walk For Women at the L.A. Memorial Coliseum on May 10, 2003.

Billy Crystal at the MLB Ten Most Memorable Moments ceremony before the start of game 4 of the World Series between the San Francisco Giants and the Anaheim Angels on Oct. 23, 2002.

Billy Crystal receives his award for favorite comedy team for his role with Robert De Niro in "Analyze This" at the Sixth Annual Blockbuster Awards in Los Angeles on May 9, 2000.