Cytokine storm<br />Cytokine storm is a general term applied to maladaptive cytokine release in response to infection and other stimuli. Cytokine release syndrome (CRS) or “cytokine storm” is a form of uncontrolled systemic inflammatory reaction that can be triggered by a variety of factors. It starts fairly quickly in cases of severe (mainly respiratory) infections, in other types of massive immune activation such as severe courses of some systemic diseases, rarely anaphylaxis. <br />The pathogenesis is complex but includes loss of regulatory control of proinflammatory cytokine production, both at local and systemic levels. The disease progresses rapidly, and the mortality is high. <br />Since December 2019, the frequent incidence of pneumonia has become a distinctive feature of the infection caused by a novel coronavirus (severe acute respiratory syndrome‐coronavirus‐2, SARS‐CoV‐2). Some evidence shows that, during the coronavirus disease 2019 (COVID-19) epidemic, severe deterioration in some patients has been closely associated with dysregulated and excessive cytokine release.<br />