Clonogenicity data showing synergistic cytotoxicity with PS-341 and 153-Sm-EDTMP against myeloma cell lines. Cells were treated with PS-341 (10 nM), 153-Sm-EDTMP (74 MBq/mL), or PS-341 and 153-Sm-EDTMP for 24 hours. Clonogenic assays were read on day 14; data are expressed relative to the colony number in the untreated sample. Error bars indicate SD.