Lady Gaga is rocking pink for a good cause.
On Saturday, the 31-year-old singer shared a selfie alongside with boyfriend, Christian Carino, but it was no ordinary photo. Mother Monster can be seen in the Instagram post rocking a sparkly pink Oscar de la Renta gown as Carino -- who she referred to as "a very special someone" -- leans on her shoulder.
The sweet photo also comes with a bit of sadness, as the singer was paying tribute to her friend, Sonja Durham. Gaga's friend lost her battle with breast cancer in May, and Saturday would have been her birthday.
"After rollin around on the couch feeling sad with the help of some of my #grigiogirls and a very special someone I managed to dress up and feel better in a beautiful pink sequined dress generously gifted to me from @oscardelarenta," she captioned the pic with Carino.
"Sonja would want us to celebrate her Birthday. So we are," the "Million Reasons" singer continued. "Dressed in Pink and handing out pink chocolate kisses for #breastcancerawareness."
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Gaga also shared a beautiful photo of the two together, writing, "I ? you forever Sonja. #breastcancerawareness #womenempowerment."
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Pink is the official color of Breast Cancer Awareness Month, which takes place every October, and Gaga shared a close up of her pretty frock in the hue, along with a necklace that held deep, personal meaning and was a way for her to feel connected to her beloved friend.
"I wear some of @sonjad7777 Sonja’s ashes around my neck in a black pearl given to me by her husband," Gaga revealed.
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Sonja and Gaga's bond was apparently very deep, as the singer pays tribute to her friend on her most recent album, Joanne, as well. The song "Grigio Girls" contains lyrics like, "Sisters never pack up/We always run back, love," as well as many other personal references to their time together.
On the same day as the Instagram posts, Mother Monster also shared a video of herself and Sonja getting emotional as htey listen to the song together.
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The 31-year-old has been facing her own health struggles that resulted in her canceling the European leg of her Joanne World Tour due to severe pain.
Her new documentary, Gaga: Five Foot Two, showcases the singer dealing with fibromyalgia, a disorder which results in chronic pain. For more on her health battle, watch the video below.