To definitively determine whether TSLP controls pulmonary levels of IL-9 and, consequently, the degree of pulmonary fibrosis, a neutralizing anti-TSLP antibody was used to block the functional effects of TSLP in the single-hit bleomycin model on day 21 after bleomycin challenge (Figure 3B–D). Here, IL9 is linked to pulmonary fibrosis.