Tumorigenesis, also known as oncogenesis, is the process by which normal cells are transformed into cancer cells. This transformation typically involves a series of genetic mutations that lead to uncontrolled cell growth, evasion of cell death mechanisms, and the ability to invade surrounding tissues and spread to other parts of the body (metastasis). Understanding the mechanisms of tumorigenesis is key to developing effective cancer treatments and prevention strategies. Researchers in this field study the genetic, molecular, and cellular processes involved in the development of cancer, as well as the environmental and lifestyle factors that may contribute to cancer formation.