Abstract: DNA polymerase iota (Polι), as well as Rev1, Polκ and Polη, are all Y family DNA polymerases, which are able to replicate damaged DNA via translesion synthesis pathway. However, Polι has the lowest fidelity among all DNA polymerases in both correct and inaccurate DNA templates. Also Polι can bypass certain DNA damages and accumulate mutations. Recent studies show that the aberrant expression of Polι is observed in human uveal melanoma, breast cancer, bladder cancer, lung cancer and esophageal cancer, which may contribute to the tumorigenesis and progression of tumor. The special role of Polι in replicating damaged DNA may contribute to the resistance in oncotherapy.

Key words: DNA damage, DNA repair enzymes, Esophageal neoplasms