Serena Williams went topless in a video on Sunday where she sings The Divinyls’ “I Touch Myself” to mark the start of Breast Cancer Awareness month.

The grand slam champion said that the video took her out of her “comfort zone” but posted it on Instagram “because it’s an issue that affects all women of all colors, all around the world. Early detection is key – it saves so many lives. I just hope this helps to remind women of that.”

According to CBS News, the video is part of the I Touch Myself Project, which is dedicated to Divinyls singer Chrissy Amphlett, who died when she was 53 years old from breast cancer.