Many today are continuing to mourn the loss of transgender actress and advocate Alexis Arquette who passed away Sunday, Sept. 11. She was 47.

The exact cause of her death was not given, but a source told People that she died from complications due to AIDS. Arquette is the sibling of fellow actors David Arquette and Patricia Arquette. Her family did not confirm how she died only that she did die surrounded by loved ones via a lengthy Facebook post written by Patricia.

David then took to Twitter about her death and thanked fans for their condolences writing, “Thank you all for your love and kind words about Alexis. My hero for eternity.”

He also posted a short clip of Alexis via Instagram with a caption which read, “Never have I had the honor of knowing and loving a funnier more beautiful soul then my brother/sister Alexis. Thank you all for your kind words of love and support. I know Alexis loves all the wonderful reactions to his passing and will be in our hearts for eternity. In the end he chose to be called my brother again but I will remember him as a Butterfly of a spirit always. I love you and in his words ‘Gracias!'”

In addition to David’s posts many other celebrities, including his ex-wife Courteney Cox, have posted their reactions to Alexis’ passing via social media.