Suppression of Gln uptake by ASCT2 pharmacological inhibitors or by shRNA-mediated knockdown of ASCT2 has been shown to successfully inhibit cancer cell growth and proliferation in a variety of tumor types including non-small cell lung cancer, prostate cancer, breast cancer, melanoma, and human head and neck squamous cell carcinoma (Cui et al. 2015; Gong et al. 2014; Hassanein et al. 2013, 2015; Lu et al. 2016; van Geldermalsen et al. 2016). This evidence concerns the gene SLC1A5 and breast cancer.