Re: Who's side are you on?
Do all mutants have to be born with the X gene? If "mutants" are, generally speaking, people born with their powers rather than gaining their powers from an external source, couldn't they be metahumans or find some other explanation? Even in the TV series "Heroes" they didn't talk in terms of an X gene.
If DC comics decided they wanted to have characters who were born with their powers, you can be sure they'd still be able to figure out a way, given that they can't use the word mutants at all.
Since the MCU isn't really the Marvel comics universe as such anyway (in that they're not free to use the methods the comics use to explain things), they have to do without things like adamantium, for which they substitute vibranium. They can surely find another way other than the X gene. Are people saying that's the only way in the world to explain people born with powers? If Marvel comics didn't even own the X-Men, they would definitely have to find another explanation if they wanted to go this route.
Teenage Mutant Ninja Turtles never talks about any X gene. And yet, are they not considered mutants within their own universe?
Anne Hathaway: "You did not just ask me that!! What a forward young man you are!!! My goodness!!"