Grey's Anatomy

In order to keep the plot and storylines secret, the main characters' names are changed in auditions.

The show was originally supposed to be called "Complications".

The character Alex Karev was not in the original pilot script; his role was inserted into the pilot as an afterthought in order to provide a foil, as well as male companionship for Dr. George O'Malley. Since he wasn't added until after the pilot was shot, scenes with him were either re-shoots or digitally altered.