Correlation between ADCC activity and the percentage of CD16⁺ cells in PBMCs from myeloma patients.⁵¹Cr-labeled RPMI 8226 cells were incubated with PBMCs from myeloma patients at an E/T ratio of 50 in the presence of 1 μg/mL humanized anti-HM1.24 MoAb. A regression line is shown (Y = 0.48X + 18.8).