William Sanderson is in X-Files.
Sanderson went on to play E.B Farnum in Deadwood.
The entire series is peppered with actors who graduated to bigger things.
Also had some recognisable names at the time - the Hollywood AD episode written by Duchovny had Tea Leoni plaing Scully in a film, and Gary Shandling playing Mulder. Obe of my favourite episodes, it was completely nuts. He’s not on screen but Richard Gere was playing Assistant Director Skinner.
He was friends with Duchovny.
Scully telling Mulder that Tea Leoni fancied him was funny, not least since they were married irl. Plus the three-way bubble bath scene with Mulder, Scully and Skinner.
