Some of today's most-beloved and iconic celebrities including Lisa Kudrow, Sarah Jessica Parker and Susan Sarandon are set to star in NBC's new alternative series "Who Do You Think You Are?" From executive producer Kudrow ("Friends," "The Comeback") in conjunction with her production company Is or Isn't Entertainment and the U.K.'s Wall to Wall productions, the series - an adaptation of the award-winning hit British television documentary series - will lead celebrities on a journey of self-discovery as they unearth their family trees that reveal surprising, inspiring and even tragic stories that often are linked to crucial events in American history.