The cancer campaigner, blogger, broadcaster and former teacher, Dame Deborah James, has died aged 40.
She had been receiving end-of-life care for bowel cancer at home and had raised millions for cancer research.
The host of the BBC's You, Me and the Big C podcast was given a damehood in May in recognition of her fundraising.
Dame Deborah, a mother of two, was diagnosed with bowel cancer in 2016. Her family described her as "amazing" and an "inspiration".
They announced her death in a post on her Instagram page. "We are deeply saddened to announce the death of Dame Deborah James; the most amazing wife, daughter, sister, mummy," it said.
She passed away peacefully surrounded by her family.
Her family said Dame Deborah shared her experience of cancer to "raise awareness, break down barriers, challenge taboos and change the conversation around cancer".
"Even in her most challenging moments, her determination to raise money and awareness was inspiring."
Watch Deborah James: Extended Interview on iPlayer.
Dame Deborah was praised for her no-nonsense approach to talking about cancer, having shared her experiences of treatment and daily life since her diagnosis in 2016.
A deputy head teacher, she started a cancer blog, before writing for the Sun and becoming a BBC broadcaster.
But on 9 May she announced that she was no longer receiving active care and did not know how long she had left.
"My body just can't continue any more," she said in a post on her @bowelbabe Instagram account.
She also launched a new fund, called the Bowelbabe fund, to raise money for research into personalised medicine for cancer patients.
It surpassed £1m in less than 24 hours - smashing her initial goal of £250,000 - and has now raised almost £7m.
In May, she was given a damehood by Prince William at her parents' home in Woking, Surrey, where she had chosen to stay.
The Duke and Duchess of Cambridge - who donated to the research fund - praised her "tireless efforts" and thanked her for "giving hope" to those living with the disease.
For her part, Dame Deborah said William's visit was "surreal".
"You can imagine the cleaning antics and preparation went off the scale - but it was all irrelevant because William was so kind," she said.
The money raised through her Bowelbabe fund will support Cancer Research UK, Bowel Cancer UK and the Royal Marsden Hospital - a specialist cancer treatment facility.
Bowel Cancer UK, of which Dame Deborah was a patron, said she had turned her bowel cancer diagnosis "into an incredible force for good" and would save countless lives through her campaigning.
Genevieve Edwards, chief executive of Bowel Cancer UK, said the former teacher had an "incredible energy" and a "marvellous knack of making things happen".
Paying tribute to the presenter's awareness-raising work, Ms Edwards said: "She had this incredible power to connect with people. She leaves a tremendous legacy behind her".
Dame Deborah campaigned to raise awareness about bowel cancer, urging people to check for symptoms, during and after her treatment.
Following one operation, while in an anaesthetic daze, she ordered a poo costume online - which she would wear while recording her podcast.
Signing off her final podcast in May, she said: "Check your poo. Come on. I can't leave on any other word apart from check your poo.
"I still have images of me dancing in poo outfits everywhere. So maybe I should leave on that final word. Check your poo."
What are bowel cancer symptoms?
- A persistent change in bowel habit - going more often, with looser stools and sometimes tummy pain
- Blood in the stools without other symptoms, such as piles
- Abdominal pain, discomfort or bloating always brought on by eating
Who gets bowel cancer screening checks?
Regular bowel cancer screening is available to everyone aged 60-74 and this programme is expanding to include everyone aged 50-59. This expansion is happening gradually over four years and started in April last year.
People in England aged 60-74 who are registered with a GP are automatically sent an NHS bowel cancer screening kit every two years.
If you are outside this age group, you should still be aware of what bowel cancer symptoms are and visit your GP if you have any concerns.
Source: NHS UK
Prime Minister Boris Johnson described her as "an inspiration to so many", while Labour leader Sir Keir Starmer said her charity work was "truly inspirational... even in the most challenging moments".
The director general of the BBC, Tim Davie said she was a "true inspiration" and the way she talked about cancer "moved the nation, inspired change and undoubtedly saved lives".
Dame Deborah began co-presenting You, Me and the Big C alongside Lauren Mahon and BBC Radio 5 Live newsreader Rachael Bland in 2018, with the show earning praise for its frank discussion of cancer.
They spoke to celebrity guests and addressed practical matters, including hair loss, tips for dealing with finances and telling your nearest and dearest about illnesses.
Bland died aged 40 in September 2018, two years after being diagnosed with breast cancer.
BBC 5 Live presenter Tony Livesey, who was a friend of Dame Deborah and did her final broadcast interview earlier this month, said the campaigner was "one of the most remarkable women I've ever met".
"All the fame she's had was a by-product of just the work she wanted to do to save one life," he told BBC Radio 4's Today programme.
BBC News presenter George Alagiah, who is living with bowel cancer, recalled speaking to Dame Deborah at the Royal Marsden Hospital.
Mr Alagiah told BBC Radio 4's Today Programme the campaigner answered his questions about the symptoms he might experience with the illness.
The newsreader said he was struck by Dame Deborah's "sheer generosity" and that their chat was "typical of what I now know she was capable of doing and did for so many others".
Speaking on BBC Breakfast, Lucie Kon, a BBC producer and friend of Dame Deborah, called the podcast host "the most amazing human out of anyone I know" and said she would be "alive in my mind forever".
Lucie said Dame Deborah showed that cancer does not have to be a "life sentence", and that the 40-year-old "didn't want to be a victim".
Dame Deborah's first book, called F*** You Cancer: How to face the big C, live your life and still be yourself, was published in 2018.
Her second book, How To Live When You Could Be Dead, is due to be released on 18 August.
Additional reporting by By Jasmine Andersson
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