**11. Future directions and implications**

Understanding DNA damage tolerance and repair will have a significant impact on elucidating the mechanisms by which DNA adducts cause mutations and genome instability. While DNA damage tolerance has been well-studied for particular types of DNA damage, such as that caused by UV and MMS, the mechanisms for DNA damage tolerance of more complex lesions is still in its infancy. The importance of studying DNA damage tolerance mechanisms for complex agents is underscored by the importance of cross-linking agents, such as cisplatin, in cancer chemotherapy. In addition, understanding how DNA damage is tolerated may have important impacts in assessing the efficacy of antifungal agents. Elucidating DNA damage tolerance mechanisms will also be important in understanding how mutations and genetic instabilities arise when cells are exposed to low doses of the DNA damaging agent. These studies should elucidate mechanisms on how cellular aging, ploidy, and cell type may affect DNA damage tolerance pathways.
