PMAIP1 and plasma cell myeloma: Given that the mechanism of BTZ-induced cell death of Onc-p53 H1975 cells is apoptotic, as is also seen in multiple myeloma cells (21), we therefore investigated whether the expression of the BH3-only proapoptotic protein NOXA, which is critical for BTZ-induced apoptosis in multiple myeloma cells (21), was also induced in NSCLC cells.