Glutamine transport is largely mediated by alanine, serine, cysteine-preferring transporter 2 (ASCT2; SLC1A5) in multiple cancers, including melanoma [8], non-small cell lung cancer [9, 10], prostate cancer [11], acute myeloid leukaemia [12], multiple myeloma [13], and breast cancer [14, 15]. Here, SLC1A5 is linked to breast cancer.