Scene 1: All cancers are genetic. Mutations in genes can be acquired by different routes; one way is inheritance of a defective gene, although inherited mutations represent the least likely pathway for cancer to develop.

Scene 2: Mutations can come from either parent -- the mutated gene in this example is in the sperm of the affected father.

Scene 3: Inherited genes can predict, to a degree, the future risk that an individual will develop different types of cancer. The mutation can be passed to future generations.

Scene 4: This family tree illustrates the inheritance of a mutated gene. The father carries one defective gene that causes cancer.

Scene 5: Each child born to the affected male has a 50 percent chance of inheriting the mutated gene, although this does not mean that those children will develop cancer.

Scene 6: Four children -- two males and one female inherited the mutated gene; again, each of their offspring has a 50 percent chance of inheriting the mutation. The mutation is inherited and those offspring are at risk for developing the cancer.

Scene 7: As a contrasting example of gene expression, when a male with a mutation marries a female with no mutation, the male with the mutation does not pass the mutated gene to future generations. They are not at risk for developing this cancer.

Scene 8: The risk of cancer in a family can depend on many factors, including the genes that are passed from one generation to the next.

Scene 9: There is risk for cancer in my family. The NCI Web site can provide more information on cancer. (http://www.cancer.gov/)

Scene 10: A family member consults with a physician who can advise on genetic testing. The physician may consult the Web and other resources.