IL6 and COVID-19: The pro-inflammatory cytokines that signal via the JAK-STAT signalling pathway include IL-2, IL-6, IL-8 and TNF-α, all of which are elevated in severe COVID-19 [50,51], as well as antiviral or anti-inflammatory cytokines such as IFN-γ and IL10, which are also elevated in severe COVID-19 [51,52].