Although, in the OlympiAD trial all subtypes of breast cancer (those with HR positive, HER2 negative disease and triple negative) had an improvement in PFS, triple negative breast cancer (TNBC) had the greatest benefit when compared to HR positive tumours: OR 0.56 (95% CI 0.34–0.98) and 0.65 (95% CI 0.47–0.91), respectively. The gene discussed is ERBB2; the disease is breast cancer.