Secrets are present all throughout Marvel Comics. Many superheroes like Spider-Man are desperate to protect their identities from supervillains, and others are even more terrified of their families facing threats. Many characters even develop secret societies meant to either protect or destroy entire sects of the Marvel universe. Whole events, including House of X, Time Runs Out, and Secret Wars, revolve around these secrets.
Source：https://www.cbr.com/good-marvel-secrets/
