CSF3 and central nervous system disorder: As in the lung of COVID-19, excessive levels of proinflammatory cytokines/chemokines might result in a “cytokine storm” that causes injury in the CNS.37 Virus invasion of the CNS leads to the induction of neuroinflammatory CNS disorder-related cytokines/chemokines, such as G-CSF,38 IL-8,39 IL-13,40 and IL-15.41 IL-15 is an immunoregulatory cytokine with antiviral properties.42 The elevated level of IL-15 observed in the infected CNS might be due to the compensatory anti-inflammatory response of IL-15 to severe diseases (Fig. 2d).