Further analysis of XRCC1 expression across breast cancer types shows increased expression of XRCC1 in Luminal (p < 1 x 10−12, Luminal to Normal) and TNBC (p < 0.001, TNBC to Normal) tumor types (Fig 1B), but not in HER2 positive tumors. Here, XRCC1 is linked to breast cancer.