Consistent with the function of FXYD6 in endowing HCC cells survival advantage (Fig. 2) in vitro, we have also shown that blockade of FXYD6 activity by its functional antibody can significantly reduce the volume and weight of xenografted tumors originated from HCC cells in vivo (Fig. 5), suggesting that FXYD6 is an important mediator in tumor development. This evidence concerns the gene FXYD6 and neoplasm.