ERBB2 and breast cancer: We found that an SD increase in TT levels increased the risk of luminal A-like BC, luminal B-like BC and luminal B/HER2-negative-like BC (OR 1.21, 95% CI 1.13–1.28, OR 1.14, 95% CI 1.02–1.26 and OR 1.21, 95% CI 1.11–1.31, respectively) (Fig. 3).