ABSTRACT
Cell proliferation occurs in most tissues throughout a lifespan and is influenced by a variety of circumstances. During this normal physiologic state, the delicate balance between cell proliferation and apoptosis (programmed cell death) is perpetuated to ensure the integrity and proper function of organs and tissues. Mutations in DNA that lead to cancer development interfere with this orderly process by disrupting its regulation. Consequently, the initiation of a cancer is due to an abnormal and uncontrolled progression of cell proliferation characterized by unregulated cell division and metastasis (spreading) of foci of cells to distant tissues.
