P53 mutants are found in more than half of human cancers and ar e considered as the most important human cancer related gene. p53 is detected at 53 kDa position by electrophoresis and is composed of 393 amino acids. In the unstressed normal cells the p53 level is low and it is inactive. However, with stress, especially with DNA damage, it is activated to promote arrest of cell cycle and repair of DNA damage, or induction of apoptosis. The functions and stability of p53 are regulated by the phosphorylation of serine and threonine, and the acetylation of lysine at various sites in the molecule. Acetylation of lysine 120 ( acetyl-K120) of p53 occurs rapidly after DNA damage and is catalyzed by the MYST family acetyltransferases hMOF and TIP60, and activates transcription of proapoptotic genes, BAX and PUMA.Synonyms: Cellular tumor antigen p53, NY-CO-13, Phosphoprotein p53, Tumor suppressor p53