They CAN affect gender, insofar as: 1.] they make the person consistently appear to be the opposite biological sex; and 2.] said person keeps all other evidence of their actual biological sex a secret. That's because "gender" is a social role which automatically applies based on your observed biological sex.

However, since 1.] is rare (esp. for men), and 2.] difficult (not to mention unethical), gender almost always goes unaffected. And, even when it is, means nothing more than exchanging one set of bogus stereotypes for the other, in any event.

Thus, in the vast majority of cases, the answer here would be: aside from the fantasy inside the person's head? Nothing.