XRCC3 and breast cancer: Notwithstanding the elusive biological significance of this finding, RAD51B and XRCC3 promoter methylation stand as candidate biomarkers for male BC, requiring further exploitation, namely in liquid biopsies by analyzing circulating cell-free DNA methylation in plasma or serum samples, which could better represent tumor heterogeneity and allow for a minimally-invasive strategy for BC detection.