Will Smith Will Smith

If you're watching TV tonight, you almost have no choice but to watch Stand Up to Cancer.

Airing on all major networks, the special will include A-listers including Will Smith, George Clooney, Reese Witherspoon, Sally Field, Laura Linney, Jim Parsons, and cancer survivor Michael C. Hall.

The broadcast is dedicated to the 12 million cancer survivors in the United States.

Marcia Cross: Cancer so doesn't care if you're famous

The telecast aims to show just how groundbreaking research can help in the fight against the disease — with CNN's Sanjay Gupta reporting on developments — while encouraging viewers to donate to the cause. Network news anchors Katie Couric, Diane Sawyer and Brian Williams are hosting.

Musical guests for the evening include Stevie Wonder, Natasha Bedingfield, Queen Latifah, Green Day's Billie Joe Armstrong, The Edge and Lady Antebellum.

Stand Up to Cancer's Laura Ziskin: "Let's get cancer out of the closet"

The special is airing commercial-free at 8/7c on ABC, CBS, FOX, NBC, Bio, Discovery Health, E!, G4, HBO, HBO Latino, MLB Network, mun2, Showtime, Smithsonian Channel, The Style Network, TV One and VH1. It's also being carried in 165 countries.

Watch the special live:

To donate to Stand Up to Cancer, text STAND to 40202, go to www.su2c.org or call 1-888-90-STAND.