X-Man is an alternate version of the regular Marvel Universe hero Cable, hailing from the alternate timeline Earth-295, first established in the "Age of Apocalypse" storyline. He is the biological son of his dimension's Scott Summers and Jean Grey, born of genetic tampering by Mr. Sinister. His first name is derived from his creator's (Mr. Sinister's) real name, Nathaniel Essex, and his last name from his genetic mother Jean Grey. Due to not being infected by a techno-organic virus as Cable was, Nate achieved vast telepathic and telekinetic powers (reflecting those that Cable would have had without the virus), and was one of the most powerful mutants in existence during his lifetime.