“Beverly Hills, 90210” stars Gabrielle Carteris, Jennie Garth and Tori Spelling are mourning the loss of their longtime co-star and friend Shannen Doherty, who died of cancer Saturday at age 53.

On Sunday, Garth shared a pair of throwback photos on Instagram of her and Doherty in character as Kelly Taylor and Brenda Walsh, respectively, on the “90210” set. In the accompanying caption, she described Doherty as “one of the strongest people I have ever known,” while setting the record straight about the longstanding perception of the two actors as adversaries.

“We were so often pitted against each other but none of that reflected the truth of our real relationship which was one built on mutual respect and admiration,” Garth wrote. “She was courageous, passionate, determined and very loving and generous. I will miss her and will always honor her deeply in my heart and in my memories.”

Carteris and Spelling, who respectively played Andrea Zuckerman and Donna Martin on “90210,” offered tributes that were more succinct, but no less heartfelt.

“So young ― so sad. May you RIP Shannen. I know Luke is there with open arms to love you,” Carteris wrote on Instagram, referring to the late actor Luke Perry, who played Dylan McKay on “90210” and died in 2019 at age 52.

As for Spelling, she wrote on her Instagram Stories that she didn’t “have outward words yet... but WE knew and that’s what matters,” alongside a recent photo of her and Doherty.

A Tennessee native, Doherty rose to fame as a child actor after landing the role of Jenny Wilder on “Little House on the Prairie” in 1982, when she was just 11 years old. From there, she made the leap to the big screen, appearing in the cult comedies “Girls Just Want to Have Fun” and “Heathers” before returning to TV as Brenda Walsh in “Beverly Hills, 90210,” which became her signature role.

In 2015, Doherty went public with her breast cancer diagnosis, and would go on to use her platform to raise awareness for cancer research.

She didn’t let her health get in the way of work, however, reuniting in 2019 with many of her “Beverly Hills, 90210” cast mates on Fox’s series “BH90210.”

“People just assume that [a cancer diagnosis] means you can’t walk, you can’t eat, you can’t work. They put you out to pasture at a very early age — ‘You’re done, you’re retired,’ and we’re not,” Doherty told People last year. “We’re vibrant, and we have such a different outlook on life. We are people who want to work and embrace life and keep moving forward.”