Describe how mutations in tumour suppressor genes can lead to the development of tumours

Tumour suppressor genes (TSGs) are genes whose protein products restrain inappropriate cell growth and division. A mutation results in a changed amino acid sequence, which alters the tertiary structure of the protein. As such, the protein has an incorrect shape, and is unable to function as it should. This results in rapid and uncontrolled cell division, causing the development of a tumour.