It's Always Sunny in Philadelphia, Season 1 Ep. 4 - "Charlie Has Cancer"
Charlie Has Cancer is the fourth episode of the American situation comedy series It's Always Sunny In Philadelphia.
It aired on August 25th, 2005 on the FX Network in the United States. The episode was written and directed by the show's creator Rob McElhenney.
This is the first episode where we see Charlie's apartment, a considerably less cluttered version than in future episodes.
The recurring character Artemis, an acting friend of Dee's, makes her first appearance in this episode. Artemis is played by Artemis Pebdani.
The recurring character Carmen, a transsexual love interest of Mac's, makes his/her first appearance in this episode. Carmen is played by Brittany Daniel, who previously starred with Glenn Howerton on the short-lived That '80s Show.
During the episode, Dee's friend Artemis constantly references the movie Coyote Ugly as she auditions for a position at Paddy's Pub. This is a reference to Kaitlin Olson's brief role in the movie.
Dennis can be heard listening to Rick Astley while he is driving in his Range Rover. Later on, the same song is used to overlay a montage of Charlie's date with the Waitress, as well as Mac's date with Carmen. In both instances, the song is Never Gonna Give You Up.