TMPRSS4 and chronic obstructive pulmonary disease: However, TMPRSS4 was upregulated in COPD as compared with HV-ES in both epithelial brushes (log2FC of 0.25, p = 0.0012) and bronchial biopsies (log2FC of 0.49, p = 0.00021) (Fig. 5c, d), but not between HV-ES and HV-NS in either epithelial brushes (log2FC of − 0.051, p = 0.55) or bronchial biopsies log2FC of − 0.13 (p = 0.56) (Fig. 5e, f).