Expression of FasR (CD95) in CD4⁺ and CD8⁺ cells from healthy volunteers versus B-CLL patients. PBMC from healthy donors (n = 20) and B-CLL patients (n = 33) were stained with FITC-conjugated anti-FasR MoAb and PE-conjugated anti-CD4 or CD8 MoAb and characterized for specific staining by FACS analysis. The percentage of CD4⁺ or CD8⁺ cells reacting with anti-FasR MoAb is shown in a box-blot and whiskers model (see Materials and Methods). Statistical analysis showed the following relationships for differences in FasR expression: CD4⁺cells: healthy versus B-CLL (P < .0001), CD8⁺cells: healthy versus B-CLL (P < .0001).