The BBC has led messages of support for magician Paul Daniels, who has been diagnosed with terminal brain cancer.
Mark Linsey, acting director of BBC Television, said in a statement: "We're sorry to hear this sad news and our thoughts are with Paul and his family."
Entertainer Daniels, 77, began his 15-year run on BBC One's The Paul Daniels Magic Show in 1979.
Earlier, a statement from his publicist said: "We can confirm that one of our greatest magicians and entertainers of all times, Paul Daniels, has sadly been diagnosed with an incurable brain tumour.
"On behalf of Paul, Debbie and their families, we thank you for your kind concerns and support at this sad time and ask that their privacy continues to be respected. There will be no further comments at this time."
BBC broadcaster Tony Blackburn was among the first of several celebrities to post messages of goodwill to magician Daniels.
"Such sad news about Paul Daniels who is a lovely and talented man. my thoughts are with you Debbie," he wrote on Twitter.
Paul Chuckle, best known as one half of children's entertainers the Chuckle Brothers, tweeted: "@ThePaulDaniels all our love to you mate !!!!!!!"
Illusionist Dynamo, real name Steven Frayne, posted his thoughts on his Instagram account.
The Bradford-born TV personality wrote: "Just read this sad news! Sending my love and respect to Paul, Debbie and all the family! #MagicLegend".
Radio broadcaster and fellow Magic Circle member Steve Allen said: "Sad news about Paul Daniels love to him and Debbie xxx."
Magician Ben Hanlin tweeted: "Really saddened to hear about @ThePaulDaniels - he is a true legend!!!!"
Comedian and broadcaster Iain Lee tweeted: "I interviewed @ThePaulDaniels. I felt he was waiting for the gag, the punchline. There wasn't one. I genuinely adored him."
Born in Middlesbrough in 1938, Daniels' interest in magic began at the age of 11 when he read a book about entertaining at parties.
After his National Service, Daniels developed his magic skills in working men's clubs.
In 1969, he was offered a summer season at Newquay and decided to become a full-time performer.
The following year, Daniels made his TV debut on talent series Opportunity Knocks, and came second.
He was seen by TV producer Johnnie Hamp, who gave him a regular slot on The Wheeltappers And Shunters Social Club, a variety show on ITV hosted by the late Bernard Manning.
Daniels married his first wife, Jacqueline, in 1960. They have three sons together.
He wed second wife Debbie McGee in 1988. They had first met nine years earlier.
McGee was Daniels' on-stage assistant from the start of his run on the BBC.
Daniels is also well known for his "You'll like this ... not a lot, but you'll like it" catchphrase. He said he first came up with the line at a club in Bradford as a way to deal with a heckler.
In addition to performing magic, Daniels hosted popular quiz shows for the BBC including Every Second Counts, Odd One Out and Wipeout.
He also narrated the children's TV show Wizbit.
In later years, Daniels and McGee participated in various TV shows including Channel 5's The Farm, ITV's The X Factor: Battle Of The Stars and Channel 4's Celebrity Wife Swap, in which Daniels tried living with Vanessa Feltz.
Daniels took part in BBC ballroom series Strictly Come Dancing in 2010. Partnered with Ola Jordan, he was the second celebrity to be voted off the show.
On Twitter, The Sun's showbiz journalist Dan Wootton said the news was "very sad".
Presenter Jennie Gow tweeted: "Very sad news about @ThePaulDaniels - grew up spellbound by him."
A tweet also appeared on the official Dick and Dom page, aka presenters Richard McCourt and Dominic Wood.
The duo are best known for presenting Bafta-award winning Dick And Dom In Da Bungalow. The message read: "Heartbreaking news of my true hero @ThePaulDaniels You inspired and encouraged me to do the job I still do today. Sending strength and love."
Presenter Suzi Perry, long associated with Grand Prix motorcycle racing coverage, tweeted "Sending love to you all xxx".