A positive correlation was found in the HFMD with encephalitis group between Dll4 expression levels in the peripheral blood and total WBC counts in CSF (R-square = 0.445, p = 0.005) as well as between Dll4 expression levels in the peripheral blood and total protein contents in CSF (R-square = 0.372, p = 0.012) (Figure 4). The gene discussed is DLL4; the disease is hand, foot and mouth disease.