The star of the Harry Potter films, Daniel Radcliffe is taking a stand against the woman who wrote the Harry Potter books: J.K.

Rowling -- over comments she made that critics said were transphobic.

Over the weekend Rowling tweeted that women menstruated -- prompting some people to respond that being a woman should not be defined by having periods.

Now, Radcliffe writes on the Trevor Project, an LGBT crisis intervention and suicide prevention charity that, quote "Transgender women are women," "Any statement to the contrary erases the identity and dignity of transgender people." He added- "We need to do more to support transgender and nonbinary people, not invalidate their identities, and not cause further harm.'' The Harry Potter author has refused to back down from her remarks.

Radcliffe said his statement is not 'in-fighting' between him and Rowling.