Previous genomic and TMA studies of large breast cancer cohorts have shown that LAT1 (SLC7A5) is a prognostic indicator of poor patient outcome in luminal B subtype only (Ring et al., 2006; El Ansari et al., 2018b; El-Ansari et al., 2019; Sevigny et al., 2019). This evidence concerns the gene SLC7A5 and breast cancer.