• Share
  • Tweet
  • Share
Kristen Wiig, Jon Hamm, Mel B

Dimitrios Kambouris/Getty Images, Stuart C. Wilson/Getty Images, Kristina Bumphrey/Startraksphoto.com

Hollywood continues to stand up for a cause that simply cannot be ignored.

As the countdown for Stand Up to Cancer's telecast continues, E! News can confirm the charity event just got even more star-studded.

Viola Davis, Jon Hamm, Kristen Wiig and Mel B are slated to attend the fifth biennial telecast set to air on September 9. But wait, there's more!

Ed Helms, Zach Galifianakis, Matt Bomer, Dave Franco, Sonequa Martin-Green, Rob Riggle, Tony Hale, Terry Crews and Bree Turner have also cleared their schedules to participate in the hour-long show airing at 8 p.m. ET/PT.

Some of the newly announced stars will have the opportunity to interact with viewers at home via the SU2C phone bank and across social media. In other words, you may just be able to chat with your favorite star if you make a simple donation.

E! News recently confirmed that Ben Affleck, Matthew McConaughey, Emma Stone, Anna Kendrick and Alison Sweeney would be participating in the fundraising event.

Céline Dion, Dierks Bentley, Keith Urban and Little Big Town will also lend their voices in special musical performances that cannot be missed.

"It's truly inspiring to see so many people come together for this cause," SU2C co-founder Katie Couric said in a statement. "We have a great show lined up this year and are grateful to the amazing individuals taking time out of their schedules to participate."

She added, "It will be a fantastic opportunity for people to learn about some of the incredible new breakthroughs in cancer research and treatment that are giving real hope to many patients and their loved ones."

Find out how you can Stand Up to Cancer and help by visiting the organization's website today.