Flow cytometric analysis of HMCL cell death induced by HGS-ETR1 or HGS-ETR2 mAbs. HMCLs (125 000 cells/0.25 mL in 96-well plates) were treated for 48 hours with 0.06, 0.6, and 6 μg/mL HGS-ETR1 (NAN-1, KMS12PE) or HGS-ETR2 (MDN) mAbs. NAN-1 and MDN were cultured with 3 ng/mL IL-6. Cells were stained with APO2.7-PE mAb and were analyzed with a FACSCalibur flow cytometer. FSC indicates forward scatter; SSC, side scatter.