CCL7 and COVID-19: Moreover, analysis of the leading edge genes in their respective GSEA contours showed that MAFB and MAF oppositely regulate the expression of chemokines that contribute to the SARS-CoV-2–induced “cytokine storm” (CCL2, CCL4, CCL7, CCL8, CXCL10, CXCL11), some of which have been already proposed as useful biomarkers for COVID-19 severity and progression (38).