R406 blocks BCR-induced secretion of the chemokines CCL3 and CCL4 by CLL cells. This bar diagram displays CLL cell supernatant concentrations for CCL3 (■) and CCL4 (□) from CLL cells cultured in medium (control), medium supplemented with anti-IgM, or medium with anti-IgM plus R406. After 24 hours, supernatants were harvested and assayed by enzyme-linked immunosorbent assay. Whereas anti-IgM induced a robust secretion of CCL3 and CCL4, treatment with R406 almost completely abrogated the secretion of CCL3 and CCL4. Displayed are the mean (± SEM) supernatant concentrations from 4 different patient samples.