IL4 and COVID-19: Researches show that the levels of IL-17, IL-1β, TNF‐α, IL-6, and IL-4 significantly increase in COVID-19 patients compared with non-COVID-19 patients or healthy people, and IL-17, IL-1, and TNF have great dependence on Th17 adaptive immune response triggering the inflammation cascades in COVID-19 (26, 94, 97, 98).