"Deadpool" has gone on to become one of the highest-rated and highest-earning R-Rated films of all time and it comes as no surprise that a sequel is already in development, bringing back Ryan Reynolds and director Tim Miller. In a recent interview with Variety the possibilities of "Deadpool 2" crossing over with the "X-Men" films was brought up.

The first movie did feature two X-Men members. Colossus (Stefan Kapicic) and Negasonic Teenage Warhead (Brianna Hildebrand) were both present in the film and the mansion that the X-Men resided in was also featured in the film. The character Cable, a mutant from the future, is also set to make his debut live-action appearance in the sequel.

Director Bryan Singer, who helmed "X-Men: Apocalypse" and "X-Men: Days of Future Past," stated that bringing in Deadpool (Ryan Reynolds) in a future "X-Men" movie is possible but has to be handled with care.

"If you take a character as irreverent and meta as Deadpool and connect him to something as grounded and serious as 'X-Men,' you have to do it carefully and gently," Singer explained. "When you drop them all in together it can be a disaster. That has to be done delicately, but there's plenty of room to do it."

This does not entirely rule out Deadpool from appearing in a future "X-Men" film and "Deadpool 2" may feature some of the "X-Men" characters, particularly Wolverine (Hugh Jackman), the currently un-cast Cable, and Beast (Nicholas Hoult/Kelsey Grammer) given that Beast was name-dropped in the first "Deadpool" movie. 

In an interview with Collider, Miller also explained that other "X-Men" characters may make an appearance although he was not sure if Deadpool's girlfriend, Vanessa (Morena Baccarin), will gain powers and become the mercenary known as Copycat in "Deadpool 2" or if she will remain purely as his human girlfriend.