The seldom-seen Terrance Steadman has been played by three different actors so far: David Lively, John Billingsley, and Jeff Perry.
The episode title "John Doe" is also the title of another TV series, John Doe (2002) in which Dominic Purcell was also the lead actor.
Paul Adelstein (Paul Kellerman) and Jeff Perry (Terrance Steadman) later acted together on the TV show Scandal (2012).
Jeff Perry (Terrance) guest starred in Columbia, season 8 episode 2. Became a John Doe in the episode.