Damage to our DNA, which can occur as a result of smoking or exposure to UV rays, can lead to increased susceptibility to certain cancers. Checkpoint proteins play a crucial role in the monitoring of damaged DNA in our cells, repair of the damaged DNA and prevention of the consequences of exposure to environmental DNA damaging agents. Understanding the mechanisms through which human cells repair DNA damage is important in the development of new diagnostic tools and novel drugs for the treatment of cancer. This programme is investigating the effects of DNA damage in the genes responsible for the protective checkpoint proteins, and the mechanisms involved in monitoring the repair of DNA damage.