Biomarkers of disease progression. ALC in panel A and serum-derived biomarkers were measured at baseline (Pre), best response (Best), and progression (PD) in matched samples: (B) B2M; (C) LDH; (D) clonal light chain (LC), either κ or λ, corresponding to the light chain restriction of the CLL cells as determined by flow cytometry; and BCR-regulated chemokines (E) CCL3; and (F) CCL4. Solid lines above each graph indicate results of Wilcoxon matched-pairs signed rank test. *P < .05, **P < .01, ***P < .001. ns, not statistically significant. PD, progression of disease.