Tumour suppressor gene example: TP53 gene
TP53 is a tumour suppressor gene which codes for the p53 tumour suppressor protein. Loss-of-function mutations in the TP53 gene are found in half of all human cancers.
If the p53 protein is knocked out (no longer produced) or damaged (e.g. through mutated) cells will continue to grow and divide. These cells are at a much higher risk of becoming cancerous.
For the p53 protein to be knocked out, both copies of the TP53 gene must mutate.
Some people inherit just one functional copy of the TP53 gene. As a result they have a much higher risk of developing cancer.