The cytokine storm phenomenon is an increase in pro-inflammatory cytokine levels in the serum, such as IL-2, IL-6 and IL-1β, IL-17, IL-8, G-CSF, GM-CSF, IP10, MCP1, MIP1α (also known as CCL3), and TNF [36], and causes acute respiratory distress syndrome (ARDS) in severe COVID-19 cases [117]. Here, CCL2 is linked to acute respiratory distress syndrome.