"XP 유전자" refers to the gene associated with Xeroderma Pigmentosum, a rare genetic disorder that affects the skin's ability to repair damage caused by ultraviolet (UV) light. Individuals with mutations in the XP gene are highly sensitive to sunlight, leading to a significantly increased risk of skin cancers and other skin abnormalities. The XP gene plays a crucial role in the nucleotide excision repair pathway, which is responsible for fixing DNA damage. When this gene is defective, the body cannot effectively repair UV-induced DNA lesions, resulting in the symptoms and complications associated with the disorder.