Munn was diagnosed with breast cancer in April 2023. She’s since undergone lymph node dissection, a nipple delay procedure and a double mastectomy. She also had breast reconstruction surgery, hormone suppression therapy, and her ovaries, uterus and fallopian tubes removed.

In March, the X-Men actress revealed in an Instagram post that she had undergone four operations, including a double mastectomy, after being diagnosed with cancer.Now, she’s partnering with the shapewear brand, founded by Kim Kardashian, to support the Susan G. Komen breast cancer charity, with 10% of each bra's retail sales going to the cause.