Which of the following is known as the guardian of the genome?

Due to its critical impoance in maintaining genetic stability p53 is called the "gatekeeper" or "guardian" of the genome. The tumor suppressor protein p53 is a key regulator, of the cellular response to geno-toxic damage, and thus plays a pivotal role in preventing cancer formation. Once DNA damage has been incurred, p53 can elicit several different responses to either correct the errors or destroy the damaged cell. 3 Impoant actions: 1. p53 can induce G1 cell cycle arrest, which stops the cell from dividing and allows time to repair the damage before the DNA is replicated. 2. p53 can activate DNA repair proteins to drive the repair of damaged DNA. 3. As a last reso, p53 can induce damaged cells to undergo programmed cell death (apoptosis), thereby eliminating damaged and potentially dangerous cells at risk for neoplastic transformation. Ref: Cancer Genome and Tumor Microenvironment, By Andrei Thomas-Tikhonenko, 2010, Page, 190