TORONTO - Betty Fox says the spirit of her son lives on in so many people who are the unsung heroes of the Terry Fox Run.

"Terry's journey was cut tragically short but he left us with the legacy of hope and the powerful example of how one person truly can make a difference," she said Thursday.

She spoke as the Terry Fox Foundation marked the 30th anniversary of the Marathon of Hope — her son's attempt to run across Canada — with a new fundraising initiative for cancer research.

An online auction will allow Canadians to bid on 30 pairs of Medallist Edition replica shoes signed by Canadian Olympians and Paralympians from the Vancouver Games.

The shoes, bearing the signatures of such athletes as speedskaters Kristina Groves and Clara Hughes, curler Cheryl Bernard and snowboarder Jasey-Jay Anderson, will be on eBay from Sept. 7 to 21.

Helen Upperton of Calgary, who won Olympic silver in the two-woman bobsled, is among those who signed the shoes. Her family first took part in the annual Terry Fox Run when she was eight years old and living in Lloydminster on the Alberta-Saskatchewan border.

"Terry Fox embodies what we hope to achieve. He's an incredible athlete, he's a hero," said Upperton.

"He inspired a country and people all around the world and that's what we were trying to do at the Vancouver Olympics as well. I guess in some way we feel like we have something in common with him," she said.

Canadians can also buy 30th anniversary shoelaces for $5 at Adidas stores across Canada, or through the foundation. Fox wore Adidas running shoes during the 143 days he pounded the pavement.

The 30th annual run is set for Sept. 19. Since 1981, $550 million has been raised by 35 million participants in more than 40 countries around the world who've laced up for the event.

Betty Fox said she and her husband Rolly know their son's dream lives on in the volunteers, runners, donors and scientists who have taken up the cause of defeating cancer.

"Knowing these numbers brings Rolly and I such great joy because they remind us that Terry's dream of a world free of cancer did not die with him in 1981," she said.

When he started out in St. John's on April 12, 1980, Terry Fox planned to run a marathon a day — about 42 kilometres — until he made it to the West Coast.

Five months later, the one-legged runner had reached Thunder Bay, Ont., but the cancer that had claimed his right leg was diagnosed in his lungs.

Fox died on June 28, 1981, at the age of 22. He is celebrated as one of Canada's most beloved heroes while his feat is honoured with runs around the globe.

His name adorns schools, roadways and statues.

"We are always gratified and uplifted by how Terry is remembered and celebrated by so many people, not only in Canada but around the world," his mother said.