Katy Perry is heartbroken over the loss of one of her longtime friends.

On Tuesday (Nov. 27), the Witness singer shared a touching eulogy for “one of [her] biggest champions and realest friends,” Angelica Cob-Baehler, who passed away after a battle with cancer on Nov. 21. She was 47.

"She was one of the strongest women I have ever known — fighting her cancer like friggin’ Rocky, enduring chemo, immunotherapy, a tracheotomy, feeding tubes for months on end, and experimental cancer treatment trials,” Perry wrote on Instagram alongside a photo of Cob-Baehler. "I watched her go through many stages for over a year, but a few things remained constant: her sarcastic/wicked sense of humor, her positive outlook, and the incredible love she had for her family."

The pop star also credited her late friend with saving her from music industry "limbo" and helping to launch her career.

"She was like a big sister to me, showing me the ropes and always having my back," Perry continued. "She never became a yes-person and was quick to check me when I needed checking — that was family. I have procrastinated posting this because it makes it feel a little too final, but I don’t believe people ever really die — she just had to leave that body behind. Out of the body, and full of spirit now. Sadly, she also left behind two amazing young girls, and an incredible husband who was the definition of ROCK through this whole process.”

Cob-Baehler was a music industry executive who previously worked at Columbia Records, EMI and Epic.

In the mid-2000s, Cob-Baehler worked to bring Perry over from Columbia, who had shelved her album, to Capitol, who released her record One of the Boys in 2008. She also worked as the creative director on Perry's Grammy-nominated, 3x Platinum-selling album Teenage Dream.

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