IL6 and COVID-19: In fact, the exacerbated immunological reaction by the host after SARS-CoV-2 infection is characterized by excessive levels of proinflammatory cytokines, such as interleukins (IL) and C reactive protein (CRP), which constitute important biomarkers for the cytokine storm syndrome characteristic of COVID-19 severity (namely IL-1β, IL-6, IL-8, IL-17, and TNFα that have been associated with severe cases of COVID-19) [16].