Interestingly, a high-throughput screen of clinically relevant compound libraries yielded a surprising result that many of the top hits that block stress induction of GRP78 in cancer were cardiac glycosides, and among them, oleandrin (OLN) was the most potent, resulting in decreased expression of the ER, cell surface, and nuclear forms of GRP78 (96, 97). This evidence concerns the gene HSPA5 and cancer.