In the US and the EU4, patients who were not tested versus tested for BRCA1/2mut were more likely to have hormone receptor—positive (HR+)/HER2− ABC (US, 94% vs. 74%, p < 0.001; EU4, 96% vs. 78%, p < 0.001), less likely to have a known family history of BRCA1/2-related cancer (US, 6% vs. 19%, p = 0.002; EU4, 10% vs. 28%, p < 0.001), and were older (US, 68.9 vs. 62.5 years, p < 0.001; EU4, 66.7 vs. 58.0 years, p < 0.001). Here, ERBB2 is linked to cancer.