We're, like, a mutated off-shoot of humanity that has this extra gene or whatever called the X-Gene and it, like, manifests differently in everyone. I got explodey powers, but some of my friends have, like, wings or laser eyes.

[And some of them have dubiously-defined superpowers like "I dunno, it's chaos magic."]

. . . Basically we're humans who have, like, biological superpowers instead of getting them from aliens or radiation or whatever.