Background：

DNA polymerase that promotes microhomology-mediated end-joining (MMEJ)， an alternative non-homologous end-joining (NHEJ) machinery triggered in response to double-strand breaks in DNA (PubMed:25642963， PubMed:25643323).MMEJ is an error-prone repair pathway that produces deletions of sequences from the strand being repaired and promotes genomic rearrangements， such as telomere fusions， some of them leading to cellular transformation (PubMed:25642963， PubMed:25643323).POLQ acts as an inhibitor of homology-recombination repair (HR) pathway by limiting RAD51 accumulation at resected ends (PubMed:25642963).POLQ-mediated MMEJ may be required to promote the survival of cells with a compromised HR repair pathway， thereby preventing genomic havoc by resolving unrepaired lesions (By similarity).The polymerase acts by binding directly the 2 ends of resected double-strand breaks， allowing microhomologous sequences in the overhangs to form base pairs. It then extends each strand from the base-paired region u