HSPA5 and cancer: Bortezomib, a proteosome inhibitor, induces ER stress and has therapeutic efficacy in multiple myeloma.[20, 21] Bortezomib also induces ER stress in pancreatic cancer cells and suppresses the UPR in these cancer cells.[22] Bortezomib also synergizes with cisplatin causing apoptosis of pancreatic cancer cells which may be mediated through enhanced ER stress via increased expression of CHOP/GADD153 and BiP/GRP78.[23]