The POLD1 gene (POLD1 stands for "DNA Polymerase Delta 1, Catalytic Subunit") is a protein-coding gene located on chromosome 19q13.3.
The POLD1 gene encodes the 125-kDa catalytic subunit of DNA polymerase delta. This DNA polymerase has both polymerase and 3'-5' exonuclease activity and plays a critical role in DNA replication and repair. Alternatively spliced transcript variants have been observed for the POLD1 gene. A pseudogene of this gene is located on the long arm of chromosome 6.