After 14 years, 20th Century Fox's X-Men franchise is still going strong, with the latest installment, X-Men: Days of Future Past, earning over $500 million worldwide since its release over Memorial Day weekend. The studio is already moving forward with the next installment, X-Men: Apocalypse, although that project could have a negative impact on another comic book adaptation, X-Force. Rob Liefeld, who created the X-Force comic books, hinted on his Twitter page this morning that X-Men: Apocalypse disrupted the development of X-Force, and that he isn't sure if X-Force member Cable will appear in X-Men: Apocalypse.

We first reported on the X-Force feature back in July, when Jeff Wadlow (Kick-Ass 2) signed on to write the screenplay and direct. The writer-director revealed in August that he wants X-Force to have an edgier tone that the X-Men franchise, and Rob Liefeld praised the script back in December, although that was the last we heard about the project.

The original X-Force lineup in the Marvel comic books included Boom Boom, Cable, Cannonball, Deadpool, Domino, Feral, Shatterstar and Warpath, with later versions including Wolverine, Colossus, Psylocke, and Sunspot. It isn't clear which superheroes will be included in the adaptation, or when it may move forward into production.

Would you like to see X-Force hit the silver screen after X-Men: Apocalypse? Chime in with your thoughts below.