DNA polymerase beta, also known as POLB, belongs to the DNA polymerase type-X family. In eukaryotic cells, DNA polymerase beta (POLB) performs base excision repair (BER) required for DNA maintenance, replication, recombination, and drug resistance. POLB has two distinct domains, the larger is the polymerase domain itself, whereas a small basic N-terminal domain contains an AP lyase activity that excises the abasic sugarphosphate residue at the strand break.