Lady Gaga posts emotional tribute to friend who died of cancer

Lady Gaga posted an emotional tribute to her friend and former assistant who passed away after a five-year battle with cancer.

The heartbroken 31-year-old shared a message on Instagram following the death of Sonja Durham on Thursday (18May17).

"Watching one of my best friends in the world show unfathomable courage, strength, and positivity while battling cancer has really changed my life," she began the lengthy post, which she shared alongside a black and white snap of Sonja with her husband Andrew Dubois.

"Thank you Sonja for inspiring me and all of us everyday with your joy. I love you so much it brings tears to my eyes just to think of all the years we've spent together backstage running the show, taking care of each other.

"You are one of a kind. I'm so proud of you. And you and Andre, your unbreakable beautiful love is what life is all about. You can see it in this photo. Wanted to share this with the world and show them what true beauty looks like. #grigiogirls #sonjadurham I love you girl. I love you so much," the Applause hitmaker concluded her heartbreaking tribute.

Sonja's husband Andrew confirmed his wife's passing in a post on Facebook on Friday, and said she died "peacefully and beautifully" in their home. She had been fighting the disease since 2012, but it later spread to her brain.

Gaga revealed during her headline set at Coachella last month that Sonja was the inspiration for the track Grigio Girl on her latest album Joanne.

"We were writing it because we were laying around one night and all the girls had gotten together, but Sonja wasn't there because sometimes we needed to get together without her, because we didn't want her to see us cry," she told the crowd at Coachella.

"So we formed this pact with each other that, when we needed to, we'd call together the Grigio Girls and cry it out. So this one's for you."