HMGB1 and COVID-19: Among them, HMGB1 and histones are abundantly studied because they significantly mediate lethal systemic inflammation, complement and coagulation activation, endothelial injury and organ dysfunction in various critical illnesses, such as sepsis [11, 12], acute liver failure [13], pancreatitis [14, 15], multiple trauma [16] and severe COVID-19 [17, 18].