DDB2 is a protein that is necessary for the repair of ultraviolet light-damaged DNA. DDB2 plays a crucial role in the cellular response to DNA damage, particularly damage induced by ultraviolet light. DDB2 forms a heterodimer with DDB1, collectively known as the DDB complex, which is essential for recognizing and binding to damaged DNA, specifically cyclobutane pyrimidine dimers. This interaction is vital for initiating nucleotide excision repair, a critical process that maintains genomic integrity and prevents mutations that can lead to cancer. Mutations in DDB2 are associated with xeroderma pigmentosum group E, a genetic disorder characterized by extreme sensitivity to sunlight and a significantly increased risk of skin cancer, underscoring DDB2′s importance in DNA repair mechanisms.