Tumor genes are genes that have the potential to cause cancer. Most normal cells will undergo a programmed form of rapid cell death (apoptosis) when critical functions are altered. Activated tumor genes can cause those cells designated for apoptosis to survive and proliferate instead. Most tumor genes require an additional step, such as mutations in another gene, or environmental factors, such as viral infection, to cause cancer. Fortunately, there are tumor suppressor genes that can regulate cellular differentiation and suppression of proliferation under normal conditions. Mutations in these genes result in unchecked cellular proliferation resulting in tumors with abnormal cell cycles and tumor proliferation. The tumor suppressor genes contribute to cancer by the inactivating of loss of function mutation.

In the present book, twelve typical literatures about tumor genetics published on international authoritative journals were selected to introduce the worldwide newest progress, which contains reviews or original researches on medical science, genetics, oncology, etc. We hope this book can demonstrate advances in tumor genetics as well as give references to the researchers, students and other related people.