SLC39A6 and breast cancer: At the protein level, basal cells display higher levels of ZnT1, ZIP1 and ZIP10 compared to normal cells; luminal cells display higher levels of all ZnT proteins ZIP3, ZIP5, ZIP6, ZIP8 and ZIP10.142 It has been suggested that the differing zinc transporter profiles and their effects on cellular zinc homeostasis may contribute to the phenotypic differences, including invasiveness, metastasis and treatment effectiveness, in breast cancer subtypes.142