IL6 and COVID-19: IL-6 is secreted by monocytes and macrophages and might play a central role in SARS-CoV-2-induced cytokine storms [46]; this cytokine inhibits the Th1 response [47], which is observed in severe COVID-19 patients [48], and it attenuates cytotoxic CD8+ T cell activity [49] and promotes differentiation and Th17-dependent virus persistence and immunopathology (Figure 5) [50].