AP BIOLOGY

Detailed explanation-1: -For example, familial adenomatous polyposis (FAP) is a family cancer syndrome caused by certain inherited changes in the APC gene. People with FAP have a very high chance of developing colorectal cancer at an early age and are also at risk of developing other kinds of cancer.

Detailed explanation-2: -The most commonly mutated gene in people with cancer is p53 or TP53. More than 50% of cancers involve a missing or damaged p53 gene. Most p53 gene mutations are acquired. Germline p53 mutations are rare, but patients who carry them are at a higher risk of developing many different types of cancer.

Detailed explanation-3: -Cancer is a genetic disease; tumor cells differ from their normal progenitors by genetic alterations that affect growth-regulatory genes. There exist 2 classes of such cancer genes: the oncogenes, which function as positive growth regulators, and the tumor suppressor genes, which function as negative growth regulators.