Cancer Man aka Cigarette Smoking Man

Appearances to date:

The abstruce Cancer Man has been keeping a close watch on The X-Files and all associated with it ie. Agent Mulder, Agent Scully and even Ass. Dir. Skinner ever since Special Agent Scully was assigned to keep watch on Agent Mulder.
Tall, gaunt, with a tendency to squint, he has contacts in the black ops operations that thwart Mulder in his investigations, but it is unclear whether he is aiding them or parrying their moves.
In "Tooms", Cancer Man broke his silence to affirm his belief in Mulder's report. He began to intervene more directly in "Sleepless", assigning Agent Krycek to keep an eye on Mulder.
It is well-known that Cancer Man will do anything to shut down The X-Files permanently. Yet in "Ascension", he tells Agent Krycek that it is better not to kill the agents outright, in the fear of "turning one man's crusade into a religion".
In "One Breath", Mulder confronts him directly after Ass. Dir. Skinner reluctantly tells him of his whereabouts. It is here that Mulder calls him Cancer Man, which name he is widely known on the Internet (even though the episode credits state him as Cigarette Smoking Man.)
"Anasazi",the second-series finale, revealed his deepest secrets to date: Cancer Man is well-acquianted with William Mulder, Fox's father. In a tense conversation, Cancer Man claims to be protecting Mulder. Yet when Cancer Man later speaks to Mulder himself, he blames Bill for authorizing "the project" that Fox is about to uncover. Hmm.....

The first is NO, William B. Davis is NOT a smoker. Davis did once smoke but quit way before The X-Files and smokes herbal cigarettes.
Davis directed and taught acting for most of his professional life until he took up some acting classes to 'brush-up' his techniques to help his teaching.
Davis was born in Toronto, started out as a child actor, then attended the University of Toronto and later the London Academy of Music and Dramatic Art. After directing theater in England for five years he returned to Canada, where he was invol ved in theater and then radio.
Davis laughs at the question of whether the character has a more conventional name. " What other name could I have but Lucifer?" he adds :) He also says that Cancer Man is not evil but is on a 'crusade to save the world.'
The Canadian native does admit that the role presents one constant challenge; his ascent which is quite noticeable. " I have to watch my vowels", Davis says.