CD4 and COVID-19: Besides, frequently reported severe COVID-19 characteristics include elevated TNFα, IL-6, IL-7, MCP-1, IP-10, G-CSF, and IL-10 concentrations, lower numbers and activity of CD4+, CD8+ cells, Tregs, B cells, and NK cells, increased number of plasmablasts and neutrophils, lower antigen presentation, and downregulated type I interferon signaling (10–15).