SLC1A5 and breast cancer: Kaplan-Meier survival estimates, based on dichotomized protein expression data, subsequently confirmed that patients with BC with high SHMT2 and high ASCT2 protein expression had significantly shorter OS (SHMT2, p < 0.001; ASCT2, p = 0.0165) and RFS (SHMT2, p < 0.001; ASCT2, p < 0.001), (Fig. 3).