"Charmed" actress Shannen Doherty shared the heartbreaking news that her best friend of almost three decades, Deborah Waknin-Harwin, died of cancer.
"Around 28 years ago when I met Deborah, she made me squeeze into very tight red patent pants. It was an instant friendship," Doherty penned in an emotional tribute to her late friend in an Instagram post on Monday. "A friendship that in 28 years has endured, grown and been cherished by us both."
The 48-year-old actress uploaded a series of photos documenting their friendship through the years, from hanging out with their families to enjoying a girls-only vacation at the beach.
"She taught me to play backgammon. She introduced me to the island of ST. Barth which started our girl trips there. She taught me that when she dressed me, I looked better lol," continued Doherty. "We were together thru boyfriends and husbands. Divorces, tears and laughter."
The "Beverly Hills, 90210" actress painted a picture of who Deborah was, not only as a friend, but as a mother to "her extraordinary daughter Olivia" and wife of "the love of her life Craig."
"She radiated beauty, intelligence and goodness," Doherty revealed further. "We grew up.... together. She was a constant. Thru my cancer and I for her when she got diagnosed 4 years ago."
The two were more than friends, noted Doherty, "We were sisters. Tied to each other by the universe, by our very essences that recognized each other instantly."
"I will miss you forever, your advice, your laughter, your frankness," Doherty concluded with a promise. "I will so miss you. I already do. I already feel it, this part of my heart missing. Deborah Waknin Harwin I love you."
In February, Doherty revealed on "Good Morning America" she was diagnosed with stage 4 breast cancer.