Leslie Charleson, best known for her iconic role as Monica Quartermaine on the long-running ABC daytime drama “General Hospital,” has passed away at the age of 79.

The beloved soap opera star’s death was announced Sunday by the show’s executive producer, Frank Valentini, via a heartfelt post on the official “General Hospital” Instagram account.

“With great sadness, I share the news of the passing of my dear friend and colleague, @lesliecharleson,” Valentini wrote. “Her remarkable career spanned nearly five decades on @GeneralHospital, and just as Monica was the heart of the Quartermaine family, Leslie was the heart of our cast and crew. I will deeply miss our daily conversations, her sharp wit, and her incredible presence on set. Our thoughts and sympathies are with her loved ones during this difficult time.”

Although an official cause of death has not been disclosed, both Variety and ABC News reported that Charleson had been battling a long-term illness. Representatives for the actress did not immediately respond to The Times’ request for further comment.