IL6 and COVID-19: In addition, several studies have investigated changes in the plasma proteome in conjunction with COVID-19 [7,8,9], demonstrating that a range of proteins, primarily those associated with neutrophil activation, complement activation, platelet function, and T cell suppression, as well as a range of proinflammatory factors upstream and downstream of interleukin-6, interleukin-1B, and tumor necrosis factor, showed significant differential expression in severe compared to asymptomatic or mild disease.