Effect of mAb and CD16 polymorphism on modulation of CD16. The mAb EC₅₀ as measured by decrease in CD16 expression was determined on NK cells from 12 subjects with various CD16 polymorphisms (n = 4 VV, 4 VF, 4 FF). (A) EC₅₀ values for AME-B, AME-D, and R grouped by polymorphism. (B) The same data with EC₅₀ values for FF, VF, and VV grouped by mAb. Horizontal lines represent the mean.