Comparison of Noxa, Mcl-1, and Bcl-xL protein in PB versus LN B-CLL. Protein lysates of 7 PB samples and 6 LN samples were subjected to Western blot analyses. (A) Blots were stained with antibodies directed against Noxa, Mcl-1, or Bcl-xL and reprobed with an antibody against β-actin as a loading control. In case of Bcl-xL, a specific staining at the upper cutting edge of the blot is visible and precluded analysis of the rightmost 2 samples. Densitometric scanning was performed, and Noxa/Mcl-1 ratios, corrected for actin levels, are indicated below the samples. The averaged Noxa/Mcl-1 ratio was significantly different between PB and LN (P = .011). (B) Averaged Noxa/actin and Mcl-1/actin ratios are separately plotted for PB and LN samples. Unpaired t test showed that Noxa ratios were statistically significant (P = .002), and Mcl-1 ratios showed a nonsignificant trend. Error bars indicate standard deviation.