Increased DTH reactivity in heparanase overexpressing transgenic mice. DTH reactions were elicited in the left ear skin of hpa-tg mice and their wild-type counterparts using oxazolone. Right ears of the same animals were treated with vehicle alone. Swelling of the challenged ears is expressed in mm as the increase over the baseline thickness measured in ears treated with vehicle alone. Challenged ears in hpa-tg mice (▵) showed a 3.5-fold increase in swelling over the baseline (▪), as compared to only 2-fold increase in wild-type mice (○), 24 hours after challenge with oxazolone. The differences between the 2 groups remained statistically significant for 3 days (n = 5 per experimental condition and time point). Data are expressed as mean ± SD. The experiment was repeated twice with similar results.