Catalytic component of the DNA polymerase epsilon complex (PubMed:10801849). Participates in chromosomal DNA replication (By similarity). Required during synthesis of the leading DNA strands at the replication fork, binds at/or near replication origins and moves along DNA with the replication fork (By similarity). Has 3'-5' proofreading exonuclease activity that corrects errors arising during DNA replication (By similarity). Involved in DNA synthesis during DNA repair (PubMed:20227374, PubMed:27573199). Along with DNA polymerase POLD1 and DNA polymerase POLK, has a role in excision repair (NER) synthesis following UV irradiation (PubMed:20227374). {ECO:0000250|UniProtKB:P21951, ECO:0000269|PubMed:10801849, ECO:0000269|PubMed:20227374, ECO:0000269|PubMed:27573199}. This is the function of POLE (DNA polymerase epsilon, catalytic subunit, ENSG00000177084).