In addition, IL-2, IL-12p40, IL-15, IL-2Rα, IL-3, eotaxin, IFN-α2, HGF, MCP-3 (CCL7), SCF, and TNF-related apoptosis-inducing ligand (TRAIL) were also significantly increased in the sera of HFMD patients. Here, IL15 is linked to hand, foot and mouth disease.