We also found that the median area of MUC5B+ mucus glands in SMGs was significantly increased in IPF patients as compared with that in control subjects [24,974.06 μm2 per HPF vs. 12,811.17 μm2 per HPF (p < 0.001)] (Figures 1D,F). Here, MUC5B is linked to idiopathic pulmonary fibrosis.