Effects of IL-1α on the formation of antigen-induced granulation tissue in the air pouch. (A) An antigen challenge was performed in the air pouch and recombinant murine IL-1α (5 μg/mouse) was injected into the pouch on day 0. (B) Skin samples from the air pouch were collected on day 4 (A) and day 11 (B) and frozen sections were prepared. The thickness of the granulation tissue is shown. □ indicates wild-type mice; ▪, MGL1-deficient mice. Mean plus or minus SE (n = 3). Treatment with IL-1α induced the formation of the granulation tissues at transient and chronic phases. *P < .05, **P < .001. ns indicates not significant.