Taking pathological complete response as the endpoint, we found that higher SLC3A2 expression was not resistant to endocrine therapy, anti-HER2 therapy, or chemotherapy (Fig. S1A-C), while BC patients with higher SLC3A2 expression benefitted less from chemotherapy when relapse-free survival at 5 years was considered (Fig. S1D-F). Here, ERBB2 is linked to breast cancer.