SLC1A5 and breast carcinoma: Extracellular glutamine is predominantly internalised by cells via the alanine-serine-cysteine transporter 2 (ASCT2), which has itself been the target of many studies, because it is overexpressed in various types of cancer cells (Liu et al., 2018a), including breast cancer, lung cancer and liver cancer (Liu et al., 2018b).