mRNA expression of H-PGDS in WT mice (A) and COX-2 in WT and H-PGDS-/- mice (B). **P < 0.01 compared with WT mice (n = 4). (C and D) Representative pictures of immunostained lung sections on day 7. H-PGDS expression was detected in neutrophils (C) and monocytes/macrophages (D). Nuclei were labeled with DAPI. Scale bar, 50 μm.