The document discusses how the photolyase enzyme repairs damage to DNA caused by sunlight. While photolyase is present in many organisms, it is not found in mammals. The document also discusses how the MutL protein helps repair DNA damage in humans by cutting out errors. This discovery could help develop tools and therapies for hereditary cancers by stimulating the MutL protein to induce apoptosis in damaged cells that cannot be repaired. Overall, the discoveries around photolyase and MutL may help in developing therapies for treating skin cancer.