Olivia Munn initially chose to keep her breast cancer diagnosis private, but she's shared plenty of powerful details since coming forward with her journey. "In February of 2023, in an effort to be proactive about my health, I took a genetic test that checks you for 90 different cancer genes," Munn wrote via Instagram in March 2024. "I tested negative for all, including BRCA (the most well-known breast cancer gene). My sister Sara [Potts] had just tested negative as well. We called each other and high-fived over the phone. That same winter I also had a normal mammogram.