One member of this family, FXYD3, not only serves to regulate ATPase function in normal physiological systems, but several studies have shown that overexpression of this member of the FXYD family is associated with a number of cancers, and has been implicated in direct action in the formation of at least one type of cancer (Yamamoto et al. 2009; Li et al. 2014; Zhu et al. 2013; Grzmil et al. 2004). The gene discussed is FXYD3; the disease is cancer.