Tithonus was the lover of Eos and a figure in Greek mythology. When Eos asked Zeus to make Tithonus immortal, she forgot to ask for eternal youth.
In the opening scene, the shots of the elevator falling down the shaft are taken from the film Speed (1994), also made by 20th Century Fox.
This was written by Vince Gilligan. At the beginning, Mulder is on a call doing a background check on a Ms. Ehrmantraut. Gilligan later used that surname for the character Mike Ehrmantraut, portrayed by Jonathan Banks in both Breaking Bad (2008) and Better Call Saul (2015).
The police photographer who knows when people will die is named Alfred Fellig. He was named after Usher "Arthur" Fellig, better known as "Weegee," a police photographer who became notorious in the 1930s and 1940s for taking gruesome crime scene photos. Like the eponymous character, Weegee owned a police scanner, which often enabled him to get to crime scenes before the police. Unlike the X Files character, Weegee had no psychic ability, although police gave him his nickname (a variation of "oujia") after joking that he was.
All of Alfred Fellig's cameras were borrowed from the University of California's Museum of Photography.