CCL2 and hand, foot and mouth disease: Furthermore, qPCR analysis revealed markedly elevated expression levels of inflammatory factors, including IL-6, TNF-α, IL-1β, CCL2 and CXCL10, in the PBMCs, lungs, skeletal muscles, spinal cord and pancreas tissues of the severe HFMD mice compared to the control group (Figures 2E–I).