DNA polymerase θ, a member of the DNA polymerase A family, features a unique structural composition, including a polymerase active domain and a helicase-like domain. This enzyme is predominantly localized in the nucleus and plays a critical role in DNA repair processes, particularly in non-homologous end joining (NHEJ) and alternative end joining (alt-EJ). DNA polymerase θ contributes to genomic stability by facilitating error-prone repair after DNA damage. Expression of this enzyme is found across various tissues and is associated with an increased risk of cancer development. Mutations or functional impairments can affect its repair capacity, leading to an accumulation of mutations.