HSPA5 and cancer: For instance, suppression of HSPA5 by siRNA increases sensitivity of tumor cells to etoposide in mice xenografted with human breast cancer.101 Moreover, Melanoma differentiation-associated gene-7/interleukin-24 (MDA-7/IL-24) and its derived peptide M4 interact with GRP78 in ER lumen to trigger ER stress response, which in turn promotes apoptosis of cancer cells.102 Injection of MDA-7/IL-24 recombinant adenoviruses (Ad.