CCL2 and COVID-19: Cytokine storm is hypercytokinemia that increases the volume of pro-inflammatory cytokines in the serum (e.g. IL-1β, IL-6, IL-12, INF-γ) and chemokines (CXCL10 and CCL2), and is correlated with pulmonary inflammation and extensive lung involvement as seen in COVID-19 patients [44].