CCL2 and COVID-19: These studies ́ results, showing a differential gene expression, have been confirmed by several other investigations reporting that patients with severe COVID-19 show elevated plasma levels of IL2, IL6, IL7, IL10, GSCF, IP10, MCP1, MIP1A, IL1β and TNFα compared to those with mild COVID-19, indicating that the release of inflammatory cytokines is critical in the progression of COVID-19 [31, 37].