My nephew, Oliver Carroll (Oli), is my motivation for running this year's London Marathon. I'm doing it to raise money for the Lily Foundation, an incredible charity who do so much amazing work caring for children like Oli.

Oli was unfortunately diagnosed with Leigh's syndrome, a mitochondrial disorder, at 6 months old. At 9 months old he was given just days to live. My brother, Brett and his wife Kayli (Oli's parents) were living in America at the time, so the next day me and my parents jumped on a flight to spend Oli's last days with him. It's hard to put into words how difficult those few days were. But being the brave little warrior that he is, and against all the odds, Oli pulled through those tough few days. We were then told that Oli's life expectancy was 3 years old. This September he'll turn 7! He's absolutely incredible. He's the bravest little boy I know and he makes me so proud to be his uncle every single day.

I want to run the London Marathon not only to make Oli proud, but also to raise some vital funds and awareness for the Lily Foundation, an amazing charity who do so much for children like Oli and families like my brother's, who are living with this on a daily basis.

Until Oli was diagnosed with a mitochondrial disorder I'd never even heard of it, but being on this journey with Oli I've learnt so much about it and how it affects him and how hard it is for families to care for children with mito. Brett and Kayli do an absolutely amazing job caring for Oli every day, I'm in awe of them both, but there is currently no cure for this disease which is debilitating and life limiting. Please help me to raise some vital funds in the hope that we can one day find a cure for this cruel disease.

Thank you so much for taking the time to read my story, any donations would be hugely appreciated.

Big love, Greg (and all the Carroll family)