Justice League and Justice League Unlimited are American animated series about a team of superheroes which ran from 2001 to 2006 on Cartoon Network. In April 2006 reruns began airing on Cartoon Network's sister channel Boomerang, and in Canada it is also shown on Teletoon every Friday night for Superfan Fridays.[citation needed] It is based on the Justice League and associated comic book characters published by DC Comics.