A 19-year-old Briton 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, died in his sleep Wednesday.
Celebrities and thousands of members of the public paid tribute to Stephen Sutton on social media, which he himself had used to spread news of his plight.
He raised more than £3.2 million ($5.4 million, 3.9 million euros) for cancer charities after cheerily documenting his illness on social media, and new donations poured in following his death.
His condition had improved last week, but he was taken back to hospital on Sunday after suffering breathing difficulties caused by tumours.
In a Facebook post announcing his death, his mother Jane Sutton said her heart was "bursting with pride but breaking with pain".
Stephen was a "courageous, selfless, inspirational son", she said in a message that was shared 120,000 times within an hour of its publication.
His Facebook page was followed by people from as far afield as Chile, Pakistan, Kenya and the United States.
On Tuesday, a post on Stephen's condition which included an update on his condition was seen by more than 13 million people in their newsfeed.
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 wishlist of activities, completing a skydive and playing drums on the pitch before last year's Champions League football 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 'trolls' 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"