Accessory component of the DNA polymerase epsilon complex (By similarity). Participates in DNA repair and in chromosomal DNA replication (By similarity). Component of the DNA polymerase epsilon complex consisting of four subunits: the catalytic subunit POLE and the accessory subunits POLE2, POLE3 and POLE4. Interaction with POLE3 is a prerequisite for further binding with POLE and POLE2.