CSE activity controls DTH. (A-B) LEW.1W rats were immunized with KLH and subsequently challenged with an intra-dermoreaction. Erythema (A) and induration thickness (B) were recorded at 24, 48, and 72 hours. ● represents untreated animals; ■, NAL-treated animals; and ▴, PPG/NAL-treated animals. Each point is the mean ± SEM of 4 animals, except for the PPG/NAL-treated group, which is the mean ± SEM of 7 animals. ***P < .001.