Tributes are pouring in for a teenager who raised millions of pounds for cancer charities with his refusal to allow the disease to prevent him from achieving a "bucket list" of wishes.
Celebrities and thousands of members of the public paid tribute to Stephen Sutton, 19, on social media, which he himself had used to spread news of his plight.
He raised more than £3 million (HK$39 million) for cancer charities after cheerily documenting his illness on social media, and new donations poured in following his death on Wednesday.
His condition had improved last week, but he was taken back to hospital on Sunday after suffering breathing difficulties caused by tumours.
In a post announcing his death to her son's 900,000 Facebook followers, his mother, Jane Sutton, said her heart was "bursting with pride but breaking with pain". Stephen was a "courageous, selfless, inspirational son", she said.
Following the announcement of his death, singer Barry Manilow described him as "an inspiring and beautiful soul", while England cricketer Kevin Pietersen said he was "an amazing, selfless and immensely inspirational young man".
Stephen, from Staffordshire in central England, was diagnosed with terminal cancer aged 15. He embarked on a quest to fulfil a wish list of activities, completing a skydive and playing drums on the pitch before last year's Champions League soccer final at London's Wembley Stadium.
Prime Minister David Cameron, who had visited him in hospital last week, said: "He was determined not to waste a minute, or an hour or a day.
"I think that is why he created this phenomenon, not just here in the UK, but right around the world - helped by social media, everyone was able to get involved, to pledge, to take part.
"A very, very bright light has gone out."
Last week, some Twitter users suggested he had "duped" them by soliciting pledges of money, while his condition had apparently improved.
He responded: "Sorry to disappoint you! So you know, I still have my cancer and it's incurable, if that makes you feel less 'duped' x"
Sutton originally set a £10,000 fund-raising target after being told his cancer was terminal in 2012. But he received over 100,000 public donations and raised his target to £1 million after a final "goodbye" message he posted on Facebook went viral.
"It's a final thumbs up from me," the teenager wrote alongside what he thought was a last picture of himself in a hospital bed.
Speaking about the money he had raised, he once told the BBC: "I don't actually do what I do for recognition. I love nice comments but I do what I do because I find the best way to help myself is to help others."
Additional reporting by Reuters