Hollywood actor Samuel L. Jackson has thrown his support behind a new children's cancer awareness campaign by lending his voice to a new public service announcement (Psa).

The Avengers star is fronting the In Play advertisements for the St. Baldrick's Foundation and Stand Up To Cancer charities, which aim to raise the profile of kids cancers and the importance of specialist care for sick youngsters for a chance at better survival rates.

Jackson, who appears in the Psas alongside four young cancer patients, says, "When I was a child in the 1950s, most kids who got diagnosed with cancer had little chance of survival. Now, there is hope.

"I am honoured to join Stand Up To Cancer and the St. Baldrick's Foundation to help educate people about childhood cancer and the importance of seeing a pediatric oncologist."