CD40LG and B-cell chronic lymphocytic leukemia: Internalization of anti-IgM beads by CLL cells appeared to be due to phagocytosis as it was effectively inhibited by cytochalasin D, an inhibitor of actin remodeling, whereas the dynamin inhibitor dyngo-4A (which blocks clathrin-mediated endocytosis) had only modest effects (Figure 3B).