Actress Lucy Rusedski will wave off hundreds of cyclists as they begin a 60-mile bike ride through Oxfordshire to raise money for a cancer research charity.
The wife of tennis ace Greg will be joined at the start of the race in Harwell by rally star Michael Ross.
Mrs Rusedski is supporting the event for Against Breast Cancer, which funds research aiming to increase survival rates and ultimately discover a vaccine against the disease.
Mrs Rusedski is currently starring alongside Emmerdale star Lisa Reilly in The Naked Truth - a play that sees five women learn to pole dance for a charity event to raise money for breast cancer.
She said: "Against Breast Cancer aren't just helping those who are affected by the disease, they are fighting a war against the disease itself. I'm absolutely thrilled to be able to do something to support this worthy cause."
Breast Cancer is now the most common form of cancer in the UK. Each year more that 44,000 women will be diagnosed and 13,000 will die of the disease.
For more information see www.againstbreastcancer.org.uk