CCL2 and viral infectious disease: Although ISCLS flares are frequently triggered by viral infections and accompanied by transient increases in circulating proinflammatory and angiogenic cytokines (e.g., TNF-α, CXCL10, CCL2, IL-6, VEGF, angiopoietin 2), the cytokine storm may have already peaked by the time the patient presents with hypotensive shock (21, 26).