(A) PCoA diagram of differences in PBMC between the COVID-19 patients and the healthy controls. (B) Volcano plot of DEGs of PBMC. Genes with adj. P<0.05 and |log2FC| > 1 are considered significantly differentially expressed, as shown in upper left and right quadrants. (C) GO enrichment results of significantly up-regulated genes in PBMC. The top 15 significant themes with adj. P<0.05 were shown here. (D) KEGG enrichment results of significantly up-regulated genes in PBMC. The top 15 significant themes with adj. P<0.05 were shown here. (E) Venn diagram of up-regulated KEGG terms in PBMC and KEGG terms of ambroxol’s targets. (F) Chord diagram of up-regulated genes and their corresponding pathways. Color beside gene name indicates range of up-regulate or down-regulate expression. (G) GSEA tests of corresponding up-regulated pathways in PBMC.