WT and Cc16–/– mice were exposed to air (7 mice/group) or CS for 8 weeks (15–17 mice/group). CS-exposed mice were treated thrice weekly with rhCC16 (8 mice/group) or vehicle (7–9 mice/group) for the last 4 weeks of the 8-week CS exposures. The expression of Il-6 (A), Tnf-α (B), Il-10 (C), Mmp-9 (D), and Mmp-12 (E) was measured in whole lung samples using RT-qPCR. Boxes in the box plots show the medians and 25th and 75th percentiles, and whiskers show the 10th and 90th percentiles. Data were analyzed using 1-way ANOVAs followed by pairwise testing with Mann-Whitney U tests. Asterisks indicate P < 0.05 vs. air-exposed mice belonging to the same genotype or the group indicated.