ERBB2 and breast cancer: Hence, the aims of this present study are to (1) determine the expression of SGLT1in different molecular subtypes of breast cancer by IHC and its association with clinicopathologic features, (2) determine how the expression of SGLT1 is affected by the HER2 status by western blot and assess the effect of SGLT1 on glycolysis in HER2+ breast cancer cell lines, and (3) investigate the role of SGLT1 in cell proliferation and patient survival via downstream signaling pathways.