Apoptosis programmed cell death.is a natural form of cell death characterized by active Participated of a cell in the process leading to its own decrepit and death. Recently studies suggested that apoptosis is a result from a set of discrete cellular events that are regulated by a cascade gene expression.Oncogenes and tumor suppressor genes are involved in this regulation. Apoptosis is closely related to cancer.Failure and bolckage of apoptosis in tumor cells could therefore be the fundamental importance in contributing not only to the evasion of physiological countrols on cell numbers, but also to the resistance both to natural defenses and to clinical therapy.