Charlie Sheen has implored Joan Rivers to "come back".
The 81-year-old Fashion Police co-host was rushed to hospital on Thursday, reportedly after she stopped breathing during a throat procedure at a clinic.
She's now been placed in a medically induced coma and her assistant has commented her condition is "stable".
Her friend Charlie Sheen took to Twitter to post some words of encouragement to the star. "@joan_rivers Please come back to us young lady. Your inimitable genius and compassion keeps a world you set in motion, a lot better every day." love and peace c sheen (sic)," he wrote.
@joan_rivers Please come back to us young lady. Your inimitable genius and compassion keeps a world you set … http://t.co/EoUzIXwtlM — Charlie Sheen (@charliesheen) August 29, 2014
He added a retro black-and-white snap of the pair on a talk show, signed by Joan.
It's thought doctors plan to bring Joan out of the coma at the weekend.
"Her family wants to thank everybody for their outpouring of love and support," hospital spokesman Sid Dinsay said in a brief statement.
"We will provide an update on her condition as it becomes available."
The comedienne is known for her cutting remarks and has often come under fire for her scathing comments about fellow celebrities.
In the past, she has branded Kim Kardashian and Kanye West's daughter North "ugly" and Hollywood actress Jennifer Lawrence "arrogant".
However, fellow fashion police co-host Giuliana Rancic, 40, has spoken out about the star's softer side.
"Joan is incredible. When I went through my breast cancer, I cannot even tell you guys how nurturing she was, how loving she was," she told E! News.
Like Charlie, many other A-listers have been taking to Twitter to express their hopes and love for Joan.
"Sending love and prayers to Joan Rivers tonight. Xxxxx (sic)," Cyndi Lauper wrote.
Sending love and prayers to Joan Rivers tonight. Xxxxx — Cyndi Lauper (@cyndilauper) August 29, 2014
Courtney Love posted: "Hang in there @Joan_Rivers So many awful gowns are going to be worn this year as bait for you pull through. Love and prayers Court (sic)"
Hang in there @Joan_Rivers So many awful gowns are going to be worn this year as bait for you pull through. Love and prayers Court — Courtney Love Cobain (@Courtney) August 29, 2014
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