Diem Brown, 32, best known for appearing on MTV’s “The Challenge,” died on Friday after a long battle with cancer. Her co-stars and friends at MTV have taken to social media to grieve and give condolences.

Brown was very vocal about her ongoing battle with cancer. In 2006, just before her first appearance on MTV’s “Real World/Road Rules Challenge: Fresh Meat,” Brown was diagnosed with ovarian cancer, which she battled while filming the show. In 2012, her cancer returned. After extensive treatment, she declared herself cancer free in 2013. In August 2014 she revealed that she’d been diagnosed with cancer a third time; the disease affected her stomach and colon.

According to People magazine, which hosted Brown’s blog about her battle with cancer, she died in New York City at 10:22 a.m. on Friday, Nov. 14. Since that time, her MTV co-stars and other reality stars have taken to Twitter to express their sadness: