Gene set enrichment analysis of transcriptional differences in circulating leukocytes from COVID19 + and COVID19− critically ill patients. a Histogram of Hallmark gene set enrichment analysis. A total of 26/50 gene sets were positively enriched in the phenotype COVID positive ( +) and 7/50 gene sets showed positive enrichment for the COVID negative (−) phenotype. Differentially regulated gene sets were ranked by normalized enrichment score (NES) and plotted against the –log10 of the false discovery rate (FDR q value). b Heat maps of the top 12 gene sets in the ranking list in a. Red indicates positive enrichment and blue indicates negative enrichment of gene transcripts.