Mulder's first hidden source of information, Deep Throat, brought out Cancerman as an enemy more then ever before. He had no name, but was nicknamed Deep Throat just like Mr. X. Mulder believed him from the beginning, but scully was a skeptic. Only in his last episode, (The Erlenmeyer Flask) when Scully work with him to save Mulder's life, did she start to trust him. Not much was known about his background, only that he worked for the CIA in Vietnam, and that he works for a secret government agency that performs experiment son humans/aliens. He had a strong influence on Mulder, and always supplied him with the evidence and information he needed. When he disappeared, most of the truth did too.
