MMP12 and Hermansky-Pudlak syndrome: Lung tissue damage (Fig. 6c-g), HPS (Fig. 6h, P < 0.001 for RSV + LPS group vs. the other groups) and AHR (Fig. 6i, P < 0.001 for RSV + LPS group vs. the other groups at methacholine concentrations of 25 mg/ml and 50 mg/ml) were all dramatically reduced in the RL + i MMP-12 group in parallel.