ERBB2 and breast cancer: Subsequently, we performed multivariate Cox-regression analysis, adjusted for established risk factors in breast cancer (age, tumor stage, nodal status, grading, tumor type, HR-status and HER2-status), and revealed that the -652DelDel variant was an independent prognostic factor for improved DFS (HR = 0.36; 95% CI = 0.174–0.726; p = 0.005; Supplementary Table 3).