Evaluation of internalization of antibody bound to CD40 on patient B-CLL cells as determined by flow cytometry. Patient CLL cells were incubated with huIgG₁ (10 μg/mL), HCD122 (10 μg/mL), or rituximab (10 μg/mL) on ice with 0.1% sodium azide to block internalization () or 37°C without sodium azide (▨) for 3 hours. Geometric mean fluorescent (GMF) intensities were measured and used as an indicator of internalization. Graph represents data from one CLL patient.