Famed Hong Kong actor Jackie Chan watches as former leukemia patient Naomi Ho, 5, demonstrates a kung-fu kick and leukemia patient Naushed Hidha, 5, looks on at the National University Hospital in Singapore in 2008. Chan attended a launch in the city-state as an ambassador of goodwill for Viva Foundation for Children with Cancer.

Cancer is one of the leading causes of death in the world, particularly in developing countries. Cancer affects everyone and imposes a tremendous burden on patients, families and societies. (© AP Images)