Correlation between mitochondrial priming and in vivo response in the PB, lymph node, and BM compartments. (A) Lymphocyte response. Correlation between percentage reduction in the absolute lymphocyte count at 6 weeks in CLL patients on the M12-175 trial and mitochondrial priming, as assessed by percentage cytochrome C loss after exposure of CLL cells (mean viability after thawing 92% [range 80% to 98%]) to BIM BH3 peptide at 0.8 μM (P = .05, R² = 0.23), in 13 evaluable patients with lymphocytosis at study entry. (B) Nodal response. Correlations between percentage reductions in the SPD of target lymph nodes at 6 weeks and mitochondrial priming (P = .19, R² = 0.14) in 14 evaluable patients. (C) Marrow response. Correlation between percentage reduction in CLL cell BM infiltrate at first restaging at approximately week 24 and mitochondrial priming (P = .01, R² = 0.63) in 9 evaluable patients.