ERBB2 and breast cancer: Germline variant frequencies for HR+HER2+ compared to HR+HER2- subtypes showed only the TP53 germline variants differed significantly between HR+HER2+ and HR+HER2- BC patients, with a pOR of 2.82 (95% CI 1.53–5.18, n=25,734), predisposing to HR+HER2+ (Figure 5).