CCL2 and COVID-19: We have also shown in our previous studies, using different multiplex magnetic bead-based immunoassays suitable for the Luminex-xMAP system, that sTREM-1, HGF, and MCP-1 proved to be key predictors for disease severity and mortality, along with IL-6, in a cohort of 153 COVID-19 patients with various forms of disease severity (mild, moderate, or severe) [5].