Mechanistically, the OLN suppressive activity on GRP78 induction strictly depends on the integrity of the Na+/K+ ATPase α3 isoform, which has protein synthesis regulatory activity and since this isoform is preferably expressed in human cancer cells, this could partly explain the enhanced cytotoxicity of OLN in malignant cells compared to normal cells (97). Here, HSPA5 is linked to cancer.