In an interview with Vanity Fair, actor Warren Beatty spoke for the first time about his transgender son.

Stephen Ira Beatty, 24, came out transgender in his teens and is now an activist for the transgender community.

“Just as Beatty was something of a sexual revolutionary in the years emerging from the strict mores of the 1950s, so his firstborn child is also a revolutionary,” Vanity Fair wrote. “Stephen, who is challenging cultural norms of sexuality, is an activist for the transgender community. Identifying as transitioned at the age of 14, he changed his name from Kathlyn Elizabeth to Stephen Ira. A poet and writer, he posted an 'Answer to Seven Questions' about his gender identity on the 'WeHappyTrans' web site.”

(Related: Warren Beatty, Annette Bening son Stephen Ira on being transgender.)

“He's a revolutionary, a genius, and my hero, as are all my children,” Beatty, who has four children, said when asked about Stephen.