Anti-cancer protein p53. Molecular model of the anti-cancer protein p53 (also known as tumour protein 53, or TP53). This protein's action at the cellular level plays a role in repairing DNA (deoxyribonucleic acid), and can be activated by and work against oncogenes (genes that promote cancer). It can also initiate cell death if the DNA damage is too great. p53 works by binding to DNA in cell nuclei, and may be used in anti-cancer treatments. Two types of models are shown here. The ribbons, arrows and sheets (solid colours) show the secondary structure and shape of the protein, while the background tubular structure (faded colours) shows the molecule's chemical structure of 1392 atoms and their bonds.