a Unsupervised hierarchical clustering of the Spearman correlation matrix of 5 immune cell clusters, 6 gene sets, 10 genes, 7 cytokines and 2 clinical parameters for the four SARS-CoV-2pos groups. b Circos plot visualizing the Spearman correlation matrix of 5 immune cell clusters, 6 gene sets, 10 genes, 7 cytokines and 2 clinical parameters for the four SARS-CoV-2pos groups. Each line represents a significant correlation with P < 0.05. Lines indicate positive (red) or negative (red) correlations. Size of nodes indicates degree centrality, with larger nodes representing higher degree. c PCA of the 4 immune cell clusters (T04, M02, M03 and M04), 2 gene sets (innate immunity: macrophage infiltration; GO: osteoclast differentiation), 5 genes (FAM110B, PAK3, PPP1R17, UTS2 and CCR5), and 1 cytokine (STC1) for the asymptomatic and presymptomatic subjects. Each dot represents a subject, colored by disease status. d Concentration of plasma MMP-1 and STC1 measured by ELISA in the asymptomatic and presymptomatic subjects of the Cohort 1. e Heatmap depicting the expression of MMP-1 and STC1 measured by ELISA in the asymptomatic and presymptomatic subjects of the Cohort 1. f PCA of the expression of MMP-1 and STC1 measured by ELISA in the asymptomatic and presymptomatic subjects of the Cohort 1. Each dot represents a subject, colored by disease status. g Concentration of plasma MMP-1 and STC1 measured by ELISA in the asymptomatic and presymptomatic subjects of the Cohort 2. h Heatmap depicting the expression of MMP-1 and STC1 measured by ELISA in the asymptomatic and presymptomatic subjects of the Cohort 2. i PCA of the expression of MMP-1 and STC1 measured by ELISA in the asymptomatic and presymptomatic subjects of the Cohort 2. Each dot represents a subject, colored by disease status. Significance in d, g was determined by unpaired Wilcoxon test. *P < 0.05.