HSP90AB1 and plasma cell myeloma: However, treatment of myeloma cells with compounds such as Hsp90 inhibitors (17-AAG, NVP-AUY922), bortezomib and dexamethasone is usually accompanied by the upregulation of other heat shock proteins such as Hsp70 and Hsp27, protecting cells from apoptosis and contributing to drug resistance [14, 173, 174].