The X-Men are a fictional team of superheroes appearing in American comic books published by Marvel Comics first appearing in The X-Men #1 published in September of 1963 and created by artist/co-plotter Jack Kirby and writer/editor Stan Lee. The team (and other faction teams) consists of mutants, a subspecies of human beings scientifically dubbed homo superior who are born with a genetic trait called the X-gene, which grants them natural superhuman abilities, generally manifesting during puberty. Due to their differences from the majority of the human race, mutants are subjected to prejudice and discrimination, which many members have fought against outside a variety of enemies, that of which includes villainous mutants, human bigots, supervillains, mystical threats, extraterrestrials, and malevolent artificial intelligence. In most iterations of the team, they are led by their founder Charles Xavier/Professor X, a powerful telepath who runs a school for mutant children out of his mansion in Westchester, New York, which secretly is also the headquarters of the X-Men. Their stories have frequently involved Magneto, a powerful mutant with control over magnetic fields, who is depicted as an old friend of and foil to Xavier, variously acting as an adversary or as an ally.