P53 (also known as protein 53 or tumor protein 53), is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms , where it regulates the cell cycle and, thus, functions as a tumor suppressorthat is involved in preventing cancer. p53 has many mechanisms of anticancer function, and plays a role in apoptosis, genomic stability, and inhibition of angiogenesis . If the P53 gene is damaged, tumor suppression is severely reduced.