In patients with HER2-enriched breast cancer, those with normal TC levels before NAC had a significantly better OS than those with high TC levels (P = 0.013, log-rank test) (Fig. 1d), and in patients with TNBC, the group with high TC levels after NAC had significantly better OS than those with normal TC levels (P = 0.014, log-rank test) (Fig. 2e). Here, ERBB2 is linked to breast cancer.