Since they were first introduced by Stan Lee and Jack Kirby in the '60s, the X-Men have long been the Marvel Universe's premier team of mutant superheroes. Throughout the years, the team has valiantly stood beside iconic heroes such as Captain America and Spider-Man and even eclipsed the Avengers in popularity before the introduction of the Marvel Cinematic Universe. However, despite their heroism, the mutant heroes have spent the majority of their careers in the unique position of being hated and scorned by the very humans they regularly risk their lives to protect.
Source：https://www.cbr.com/x-men-fall-of-x-killers-marvel/
