Chronic asthma was established by challenging OVA sensitized mice for 12 weeks twice weekly. OVA challenge was then discontinued and replaced with PBS for four or eight weeks. Outcome measurements were made at either 12 (+ 0), 16 (+ 4) or 20 (+ 8) weeks of challenge (Figure 1, Protocol B). (A) Representative photomicrographs of haematoxylin & eosin (H&E) stained sections (arrows indicate eosinophils, (B) immunohistochemical staining of CD3, (C) periodic acid-Schiff (PAS), (D) Sirius Red staining and (E) immunohistochemical staining of smooth muscle actin (SMA). (F) Histological quantification of lung inflammation, (G) eosinophil numbers as determined by morphological criteria in H&E stained lung sections, (H) CD3+ lymphocytes, (I) fraction of basal membrane (BM) covered by goblet cells, (J) collagen deposition and (K) SMA thickness. Box and whisker plots show mean and percentiles of n = 6–8 animals per group, *p≤0.05, **p≤0.01, ***p≤0.001.