The X-Men are a team of science fictional comic book characters, superheroes in the Marvel Comics universe. Created by Stan Lee and Jack Kirby, they debuted in The X-Men #1, published in September 1963. The X-Men are fictitious American mutants who, as a result of a sudden leap in evolution, are born with latent superhuman abilities which generally manifest themselves at puberty. In the stories, many ordinary humans harbor an intense fear and/or distrust of mutants (often referred to as Homo superior), who are regarded by a number of scientists as the next step in human evolution and are thus widely viewed as a threat to human society. The tensions are exacerbated by mutants who use their powers for criminal ends. The X-Men was formed by the benevolent Professor Charles Xavier, (a.k.a. Professor X), a wealthy mutant who founded an academy to train young mutants to protect themselves and the world from Magneto, the Brotherhood of Mutants and other mutant threats.