Dose-response of 8226/S and 8226/Dox40 myeloma cells with the anti-Fas antibody CH-11. 8226/S or 8226/Dox40 cells were incubated with the indicated dose of CH-11 antibody for 16 hours at 37°C. Cell death was assayed by flow cytometry of 7-AAD–stained cells, and the percentage of apoptotic cells (7-AAD^bright) was quantitated using LYSYS II software. Values are Fas-induced apoptosis minus nonspecific cell death. Each point represents the average of at least three independent trials.