In human genetics, TP53 is the gene often called the “guardian of the genome.” Its protein, p53, helps protect cells from becoming cancerous when DNA is damaged.
The TP53 gene provides instructions for a tumor-suppressor protein that can pause the cell cycle, activate DNA repair, or trigger programmed cell death. These responses prevent damaged genetic material from being copied and passed to daughter cells.
TP53 is located on the short arm of human chromosome 17 and encodes a transcription factor. Mutations that disable both copies of the gene are found in roughly half of human cancers, making TP53 one of the most frequently altered genes in cancer biology.
A common mix-up is treating TP53 and p53 as identical terms: TP53 is the gene symbol, while p53 usually refers to the protein it produces. Li-Fraumeni syndrome is a rare inherited cancer-predisposition condition associated with germline TP53 mutations.