Stan Lee has confirmed Marvel Studios are looking to get the rights back for 'Fantastic Four' and 'X-Men'.
Both of the film franchises are currently owned by 20th Century Fox but the 94-year-old Marvel Comics legend - who is responsible for co-creating many of the company's most famous characters, including the members of the two superhero squads - is optimistic that they will be returned to Marvel, according to comicbook.com.
Speaking at Wizard World Comic Con, in Nashville, Lee said: "Sooner or later, they're going to get the rights back to all our characters. They're working on it, and they're still making 'X-Men' movies and stuff. Don't worry about it. You'll get more Marvel superheroes than you'll have time to look at in the next few years."
Although the 'X-Men' franchise has been quite successful with both the Bryan Singer trilogy and the 'First Class' movies, however, Marvel does still have an input while making the films.
Fox needs Marvel to sign off on all TV deals regarding the superheroes, however, since the Marvel owns 'The Avengers' there has been some overlap with characters such as Quicksilver and Scarlet Witch - who have been members of both teams in the comics.
Unlike the popular 'X-Men' franchise, the 'Fantastic Four' films haven't been as popular at the box office.
In 2015, the franchise was rebooted starring Miles Teller, Jamie Bell, Kate Mara and Michael B. Jordan as the titular Four, however, the film was poorly received by fans and critics alike.
Fox owns the complete rights to the franchise and any new character within its universe belongs solely to the studio - which led to the cancellation of the 'Fantastic Four' comic series.
These two franchises are not the only Marvel comic book heroes that belong outside of the Marvel Studios, with 'Spider-Man' being owned by Sony Pictures.
However, 2017 saw the first time Marvel Studios and Sony have worked together on the fan favourite superhero after Marvel sold the rights in 1985 for $225,000, with 'Spider-Man: Homecoming'.
This collaboration meant that Tom Holland - who portrays the webslinger - is part of the Marvel Cinematic Universe rather than Sony's.