In the teaser, Pusher appears amused while looking at a magazine cover showing Flukeman, the monster of The Host (1994). The caption under the picture explains its ultimate fate.
When Mulder is fitted with a head camera, the script originally called for him to ask if the camera could pick up the Discovery Channel. Knowing Mulder's penchant for pornography, David Duchovny improvised and changed the reference to the Playboy Channel.
At one point during the episode, Mulder and Scully identify a phone number the Pusher had called to be that for a golf driving range and pro-shop. Scully quips, "So he's a killer and a golfer." To which Mulder replies, "Rings a bell, huh?" This is a not-too-subtle reference to O.J. Simpson, alleged murderer and avid golfer.
Vince Gilligan remembers he told Chris Carter, "This is the best work I'm gonna do for you." He also remembers that Carter was annoyed when he heard it and said, "Don't say that. Don't think that way. You've always got to better yourself "
"Let your fingers do the walking..." was a slogan for the Yellow Pages phone book. That is why Mulder and Scully look at the phone book after receiving that clue.
Dave Grohl: the leader of the rock band Foo Fighters and ex-drummer of Nirvana, appears behind Modell when he is entering the FBI Building. In the previous week's Apocrypha (1996), the term "foo fighter" was used as a slang term by American World War II fighter pilots to describe a UFO.