TP53 is a gene that functions as a tumour suppressor. One of its jobs is to create the p53 protein, which acts to kill cells that have become cancerous. When the TP53 gene goes wrong, it means the body loses one of the key mechanisms it has for stopping damaged cells becoming cancers. Many people who develop cancer end up having the TP53 gene damaged in their tumours, but it functions normally in the rest of their body. However, there are some people who are born with a damaged TP53 gene, and for these people the risk of getting cancer is incredibly high. In many of these cases the damaged TP53 gene is inherited – it is passed down from parent to child.

Li Fraumeni Syndrome (LFS) is one of the most serious forms of inherited TP53 disorder. Other related conditions include Li Fraumeni-like Syndrome – this has a similar increased risk of cancer development but the risk is not associated with TP53 directly but with other related genes.