FXYD5 and breast cancer: FXYD5 affects the functional properties of the Na+/K+ -ATPase activity that is implicated in many pathophysiological conditions, including cancer.36 Enhanced expression of FXYD5 reduced cell-cell adhesiveness in vitro, and enhanced the metastatic potential of liver, pancreatic and breast cancer cell lines in vivo.7,37,38 Moreover, the prognostic potential of FXYD5 has been investigated in several clinical studies and its overexpression has been significantly associated with poor outcome in different types of carcinoma.7