Activated memory T cells were associated with favourable outcome in all subgroups except ER+/HER2− tumours (HR 1.0, 95% CI 0.92–1.08), with the largest effect observed in the ER−/HER2+ subgroup (HR 0.73, 95% CI 0.60–0.89; pheterogeneity = 0.022). The gene discussed is ERBB2; the disease is neoplasm.