LISTEN: 'I owe my life to Cancer Research' says marathon running survivor
Heather Duff beat cervical cancer and is running the London marathon today.
More than 35,000 runners are taking to the streets of London today as the city hosts the annual race.
Amongst them will Heather Duff, 29, who is running her second marathon.
However this time tackling the 26 miles she's a different person; she's a cancer survivor.
Heather, from Kirkintilloch, was diagnosed with a rare form of cervical cancer in 2013 and says this time training has been like being in a completely different body.
She told Clyde News; "My body is a bit more battered this time, but mentally I am so much stronger going into it."
Heather was diagnosed at just 27 and was told she had to buck the trend in order to survive the treatment.
Luckily after months of strain and hospital visits she was told the doctors had managed to reduce the tumour, with no evidence of disease left.
Sadly the consequences of having cancer are long lasting, and dealing with the future side-effects is a challenge for Heather.
All of this makes her more determined. Now she's running the London marathon raising money for Cancer Research, the charity she says she owes everything to.
You can hear her talk to our reporter Shiona McCallum here: