Gene signatures and expression of ACE2, TMPRSS2 and FURIN
To further determine the relationship between gene signatures of interest and the expression levels of ACE2, TMPRSS2 and FURIN, we measured by GSVA the ESs of IL-13-Th2, eosinophil activation, IL-17, neutrophil activation, IL-6-trans-signalling (IL-6-TS), and inflammasome signatures (Supplementary Table S2 ). The ES of IL-13-Th2 signature was positively correlated with ACE2, TMPRSS2 and FURIN levels in the majority of compartments analysed (Table 2 ); however, the ES of eosinophil activation signature only weakly correlated with ACE2 in sputum (r =0.18, p <0.05) and with FURIN in bronchial biopsies (r =0.26, p <0.05). FURIN levels in all 3 compartments correlated with neutrophil activation and IL-6-TS signatures, with the highest correlation in sputum (Table 2 ). Spearman’s correlation coefficients (r ) between sputum FURIN levels and the neutrophil activation and IL-6-TS signatures were r =0.53 (p <0.001) andr =0.56 (p <0.001), respectively (Fig 3B and 3C ). Inflammasome activation also correlated with FURIN levels in sputum (r =0.49, p <0.001) and in bronchial brushings (r =0.30, p <0.001; Table 2 ).