"Yes, the timeline is different. It wouldn't physically fit for him to be the brother of Cyclops. We take some liberties on that. There are notions, but, um, I don't want to give away certain interrelations, but let's just say there are some things that do adhere to the comic books and do so in a way the fans will get a kick out of. And those things can, perhaps, move forward into the future," said Singer.
He added that he really likes Lucas Till (who played Havok), which he described as "very cool" and "bring on some continuity in different time than the comic books". He described that the "First Class" period is when the characters haven't honed their ability yet, it's about recruiting the mutants and bring them together.
Singer also talked about the characters that previously appeared in first to third X-Men movies, but in younger version. "We have younger versions of Mystique and Beast, so I'm very excited about them and what they bring to the film. Jennifer Lawrence's work [as Mystique] and Nicholas Hoult's portrayal of Beast - these are characters that we've seen in the earlier films, but then these are very different portrayals and you have to bring a lot of attention to those."
