Members of Hollywood's A-list are joining forces for a good cause. According to People magazine, Meryl Streep, Jennifer Aniston and Charlize Theron are among the celebs who've agreed to participate in the Stand Up to Cancer telethon, airing September 5 simultaneously on ABC, CBS and NBC.

Scarlett Johansson, Christina Applegate, Sally Field and "American Idol" champ David Cook are also expected to appear on the show, which will raise money for cancer research and treatment.