Rationale The acetylation level of XRCC6 is significantly decreased in clinical breast cancer tissues compared with paracancerous tissues; however, the relationship between this alteration and the occurrence and development of breast cancer remains unclear. Methods Acetylproteomics was employed to detect changes in protein acetylation levels in clinical samples. Co-immunoprecipitation (Co-IP) assays were utilized to identify the acetyltransferase and deacetylase responsible for XRCC6 K591 acetyl