Expression of Fas-R (CD95) in HIV-1 infection. Samples of blood were obtained from a group of 86 HIV-1–infected patients and a group of normal blood donors and stained with FITC-conjugated CD95 MoAb and PE-conjugated CD4 or CD8 MoAb. The percentage of CD4⁺ cells (A) or CD8⁺ cells (B) reacting with CD95 MoAb is shown. Statistical analysis showed the following relationships for differences in Fas-R expression: CD4⁺ cells: control v HIV-1⁺ (P < .01), CD8⁺ cells normal control v HIV-1⁺ (P < .01; Wilcoxon two-sample test).