Based on these observations of HIS, various types of anti-cytokine therapies were evaluated in COVID-19 patients, including anti-interleukin-6 (IL-6) [6], anti-interleukin-1 (IL-1) [7] and anti-granulocyte-monocyte colony-stimulating factor (GM-CSF) [8]. Here, IL6 is linked to COVID-19.