There is an apparent enrichment for HER2-overexpression, and particularly “triple positive” (ER+, PR+ and HER2+) breast cancers —compared to the general population, in which HER2-overexpressing breast cancers account for 20–30% of cases, 63–83% of breast cancers in carriers of pathogenic TP53 variants are HER2-amplified [48,49]. The gene discussed is ERBB2; the disease is breast carcinoma.