SLC3A2 and biliary tract cancer: SLC3A2 is highly expressed in various cancer types, including gastric cancer,9 osteosarcoma,10 renal cell carcinoma11 and biliary tract cancer.12 Previous studies of SLC3A2 in human breast cancer (BC) showed its prognostic significance but in a limited number of cases.13, 14 To our knowledge there is no prognostic analysis, which involves the impact of SLC3A2 overexpression in large cohorts, including the different BC molecular subtypes.