A two-day vigil for 19-year-old Stephen Sutton, who succumbed to multiple tumours earlier this month, is due to start today.
Mr Sutton's bravery in facing his terminal illness while urging people to enjoy life has now become a global phenomenon reaching more than five million people worldwide, according to one social media website.
His mother Jane Sutton said: "The continued love and support for Stephen is wonderful and a great comfort."
She called on people to "do something that makes you and others happy in Stephen's memory" at 11am tomorrow. The Thumbs Up For Stephen event will follow a vigil at Lichfield Cathedral in Staffordshire, which starts at 7pm tonight.
Mr Sutton's campaign to raise money for the Teenage Cancer Trust attracted huge support. Prime Minister David Cameron met him in hospital, and following his death on May 14 said: "He was absolutely inspiring."