The fraction of proliferating lymphocytes was higher among anti-FasL–treated animals. (A) The CD4 Ki-67⁺ lymphocytes showed an increase in both groups after the peak virus replication phase, with significantly more cells in anti-FasL group at 4 and 6 weeks after infection. (B) The CD8 Ki-67⁺ lymphocytes were highest at the time of peak virus replication for both groups; anti-FasL–treated animals had significantly higher percentages of this subset at 2, 4, and 6 weeks after infection. *P < .05. Error bars indicate SEM.